JPS63305117A - Melamine resin, its production and melamine resin molding material - Google Patents

Abstract

PURPOSE:To obtain a melamine resin increased in flexibility and improved in impact strength and insert crack resistance, by modifying a melamine resin with a glycidyl compound. CONSTITUTION:This melamine resin is obtained by reacting melamine with formaldehyde and is modified with a glycidyl compound. To produce this melamine resin, melamine is first reacted with a glycidyl compound, and the product is reacted with formaldehyde. Said modified melamine resin is mixed with a base material such as an organic or inorganic filler to form a melamine resin molding material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a melamine resin with improved flexibility, a method for using the same, and a melamine resin molding material.

[Background Art J] Melamine resin has been used for a variety of purposes since it has excellent mechanical strength, electrical properties, and colorability. However, melamine resin has low flexibility and poor toughness, and has problems in terms of impact strength and insert crack resistance. For this purpose, attempts have been made to modify the melamine resin with rubber or with 7 ether, but so far no sufficient effect has been achieved.

[Object of the Invention] The present invention has been made in view of the above points, and provides a melamine resin with increased visibility and improved impact strength and insert crack resistance, a method for producing the same, and a melamine resin molding method. The purpose is to provide materials.

[Disclosure of the Invention] The melamine resin according to the present invention is a melamine resin obtained by reacting melamine and formaldehyde, and is characterized in that it is modified with a glycidyl compound. The method for producing a melamine resin according to the present invention is characterized by reacting melamine and a glycidyl compound, and then reacting this reactant with formaldehyde, and furthermore, the melamine resin molding material according to the present invention is characterized by reacting melamine with a glycidyl compound, and then reacting the reaction product with formaldehyde. It is characterized by being made by blending a melamine resin modified with and a base material.

The present invention will be explained in detail below. Examples of glycidyl compounds include ethylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol glycinole ether, neopentyl glycol diglycidyl ether, nool glycidyl ether, These include trimethylolpropane polyglycinole ether and polyethylene glycol diglycidyl ether.

In the present invention, melamine resin is modified with this glycidyl compound, and in preparing the melamine resin modified with the glycidyl compound, melamine and the glycidyl compound are first reacted as a secondary reaction, and then as a secondary reaction. This can be carried out by reacting this reactant with formaldehyde. Here, in the next reaction, the epoxy group of the glycidyl compound opens the ring and dehydrates the 7mi/group of melamine to add H2? \N/H2 ■ Also, the secondary reaction is thought to occur due to the dehydration addition of formaldehyde to the unreacted amino groups of melamine, as shown in formula (n).

In H-CHO Niko, the next reaction is 10-1 at a temperature of about 80-100℃.
It is desirable to set the conditions so that the reaction takes place for about 50 minutes, and the secondary reaction is carried out at a temperature of about 70 to 90°C for 5 to 50 minutes.
It is desirable to set conditions so that the test lasts about 60 minutes. In addition, the blending amount of each component in the above reaction is as follows: where the number of moles of melamine is M, the number of moles of glycidyl compound is G, and the number of moles of formaldehyde is F, the molar ratio of glycidyl compound to melamine is G/M=
0.0 1 to 5.8 It is desirable to set the range so that the molar ratio of formaldehyde to the difference in the number of moles of melamine and glycidyl compound is F/I M - G l =0.5 to 4.0. .

The molar ratio of glycidyl compound to melamine is 0.

If the molar ratio is less than 5.01, the modification by the glycidyl compound will be insufficient, and the effect of increasing the flexibility and toughness of the melamine resin will not be sufficiently obtained.
If it exceeds 8, the amount of the glycidyl compound in the reaction system becomes too large and tends to gel due to the action of the amine, and similarly, the effect of increasing the visibility and toughness of the melamine resin cannot be sufficiently obtained. Generally, the number of moles M of the melamine resin is set larger than the number G of moles of the glycidyl compound. Furthermore, if the molar ratio of formaldehyde to the difference in the number of moles between melamine and the glycitol compound is less than 0.5, the amount of formaldehyde blended will be insufficient and the melamine resin will not be able to be sufficiently cured, and if this molar ratio is 4.
．． If it exceeds 0, there will be too much formaldehyde and the crosslinking density of the melamine resin will become too high (too much), making it impossible to sufficiently obtain the effect of increasing the flexibility and toughness of the melamine resin.

The product obtained by this reaction is in the form of a melamine resin, and in addition to being able to be used as is as a glycidyl compound-modified melamine resin slate, this slag can also be used as a glycidyl compound-modified solid melamine resin by dehydrating it. . During dehydration, it is best to allow the reaction to further polymerize the resin to proceed, and for this reason, it is preferable that dehydration be performed using a method that involves heating. method, spray dryer method, WEF method (
Dehydration methods that include heating operations, such as thin film evaporation (thin film evaporation), are preferred.

When the melamine resin is used in the production of Ht laminates, decorative laminates, or other paints, it is possible to use the above melamine resin in the form of a silage, or after kneading this silica with a base material and drying it. It is also possible to prepare a molding material by mixing this with other ingredients such as a mold release agent and a hardening agent, and then subject this molding material to compression molding or the like to produce a molded article. It is also possible to prepare a molding material by crushing the dehydrated and dried melamine resin and mixing it with a base material, other mold release agents, curing agents, etc., and then subjecting it to compression molding in the same way to create molded products. Monkey. Furthermore, the dehydrated and dried melamine resin can be molded into a pure resin molded product without adding a base material, and in this case, in addition to compression molding, there is no need to worry about the molding method such as transfer molding or innoexy layer molding. Can be molded. The above-mentioned base materials include organic fillers such as pulp, wood flour, paper, and thread waste;
Inorganic fillers such as asbestos, mica, and plus fibers can be used.

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

Dog 1" [L Melamine 1500g1 Polyethylene glycol noglycinol ether 750g, Water 1430g. were charged into 51 three-bottle flasks, and heated to 95°C.
After reacting for 1 minute, add 40% formalin to this for 19 minutes.
After injecting 35 g, the temperature was raised and the reaction was carried out at 85° C. for 35 minutes to obtain a melamine resin sill modified with a glycidyl compound. In this formulation, G/M=0.
12, and F/(MG)=2.4.

100 parts by weight of this melamine resin sill was taken, permeated into 20 parts by weight of pulp with a Nigu, crushed, and further dried in a hot air dryer at 110° C. for 1 hour to obtain a dried product of 1 liter. This was further mixed with 0.6 parts by weight of zinc stearate as a mold release agent and 0.2 parts by weight of 7-talic anhydride as a hardening agent and ground in a pot mill to obtain a melamine resin molding material.

Dog 11'' - The amount of each ingredient was melamine 1500. , 600 g of polyethylene glycol diglycyl ether.

Other than setting it to 1950g of 40% formalin,
Melamine resin sills were prepared in the same manner as in Example 1,
Furthermore, a melamine U (layer molding material) was obtained in the same manner as in Example 1. In this formulation, G/M = 0.1, F/(
M−G)=2.0.

The powdered melamine resin molding materials of Examples 1 and 2 obtained as described above were molded in accordance with JIS K6911 using a 37t press molding machine at a mold temperature of 165°C for 2 minutes, and then tested. Created a piece. The Charpy impact strength and DuPont impact strength of this test piece were measured in accordance with JIS K 6911. The results are shown in Table 1. For comparison, CP-9 manufactured by Matsushita Electric Works Co., Ltd. was used as an unmodified melamine resin.
012, and the rest is 1it9I in the same manner as in Example 1.
Similarly, the results of Charpy impact strength and Derovon impact strength of the melamine resin III molding material (Comparative Example 1) shown in Table 1 show that Examples 1 and 2 using glycidyl compound modified melamine resins The impact strength is improved compared to that of Comparative Example 1, which is a melamine resin that is not modified with a compound, and it is confirmed that modifying the melamine resin with a glycytyl compound can have the effect of increasing the flexibility of molded products. .

Dog 3-6 The glycidyl compound-modified melamine resin stubble obtained in Example 1 was placed in a vacuum Neegoo, dehydrated by vacuum heating by reducing the pressure to 60-mHg and heating with 200°C steam, and modified with a glycidyl compound. A solid melamine resin was obtained.

This solid melamine resin was then mixed into a molding material containing an unmodified conventional melamine resin (CP-9012 mentioned above). The molding material is 210 Oat parts of melamine resin melamine resin (CP-9012), 900 parts by weight of pulp, 20 parts by weight of zinc stearate as a mold release agent, and 0.4 parts by weight of 7-talic anhydride as a hardening agent, and then processed in a bot mill. The molding material is melamine resin (CP).
-9012) and pulp, of a total of 1100 parts by weight,
The above-mentioned glycidyl compound-modified solid melamine resin contains 1 part by weight (Example 3), 20 parts by weight (Example 4), and 50 parts by weight (
Example 5) The mixing amount of this glycidyl compound-modified solid melamine resin was set so that it could be replaced with each other. Furthermore, a product made of 100% of this resin (Example 6) was prepared by replacing all 100 parts by weight with a solid melamine resin modified with a glycicul compound (Example 6), and for comparison, a solid melamine resin modified with a glycicul compound was also blended. The one that does not (comparative example 2) is also 11! I did it. JIS K 691 using the powdered melamine resin molding materials of Examples 3 to 6 and Comparative Example 2 obtained as described above.
1, the mold temperature is 165℃ using a 37t press molding machine.
A test piece was created by molding for 2 minutes. The DuPont impact strength, flexural modulus, and crack resistance of this test piece were measured in accordance with JISK 6911. In the crack resistance test, a test piece is created by molding the metal material inserted in the mold at a mold temperature of 165°C for 2 minutes, and then the test piece is placed in a dryer at 110°C for 1 hour.
The process of heating for a period of time, then taking it out and cooling it in the air was repeated, and the evaluation was made according to the number of processing cycles until cracks appeared, and those that cracked in one cycle were marked "x", and those that cracked by the fifth cycle were evaluated. Things"
Δ", and those in which no cracks occurred after 5 cycles were marked with "○". As seen in Table 1 above, the most significant feature of the glycityur compound-modified melamine resin of the present invention is that it can increase the flexibility and impact resistance of molded products as described above. This is also supported by the results in Table 2. That is, compared to Comparative Example 2 using only conventional unmodified melamine resin, Examples 3 and 4
．． 5, by blending a melamine resin modified with a glycytyl compound with this unmodified conventional melamine resin, the flexibility of conventional melamine resin molded products can be increased and the impact resistance and insert crack resistance can be improved. This means that it will be possible to do this.

To 100 parts by weight of solid melamine uI fat, prepared in the same manner as in Examples 3 to 6, was added 0.6 parts by weight of zinc stearate as a mold release agent, and 7 talic anhydride as a hardening agent. 0
．． A powdery melamine resin molding material was obtained by adding 2 parts by weight, mixing and pulverizing this in a bottle mill.

The melamine resin slag obtained in Example 2 of "Dog 11" was added to the above "Example 3".
A solid melamine resin is made from IW by drying it in the same manner as in ``6'', and this solid melamine resin is used in the following ``
A powdered melamine resin molding material was obtained in the same manner as in Example 7.

Using the melamine resin molding material obtained in Example 7.8 above,
In accordance with JIS K 6911, a test piece was made using a 37t press molding machine at a mold temperature of 165°C for 2 minutes, and the bending strength, flexural modulus, Charpy impact strength, DuPont impact strength, and appearance were measured. Gloss and crack resistance were measured. For comparison, the same measurements were also carried out on the melamine resin molding material of Comparative Example 1, which was manufactured using the above-mentioned CP-9012 as the melamine resin.

The above results are shown in Table 3.

Since melamine resin alone is brittle, it is generally difficult to mold it unless mixed with a base material such as pulp. However, since the melamine resin modified with the glycidyl compound according to the present invention has flexibility, As shown in 7.8, another major feature is that the resin can be molded alone without being mixed with a base material such as pulp.

As shown in Table 3, the molded product has high strength, high elasticity,
It has impact resistance, good appearance, and crack resistance, making it ideal for molded products such as tableware, and since it does not contain a large amount of base material, compression molding (direct pressure molding) and Transformer 77 can be used as molding methods.
-In addition to molding, there is no need to choose a molding method such as injection molding.

Also, an example? And the melamine resin molding material obtained in Example 8 was press 10 in accordance with JIS K 6911.
A test piece was prepared by injection molding under the conditions of 0t, mold temperature of 165° C., and 2 minutes, and a compression fracture test was performed. 4 test pieces each for Examples 7 and 8 (Nol to N.

4) Created and tested each. In addition, for comparison, a melamine resin molding material was prepared in the same manner as in Example 7 using a conventional unmodified melamine tree Wt (CP-9012) (Comparative Example 3), and the same procedure was applied to this material. A test was conducted. The results are shown in Table 4.

As shown in Table 4, a major feature of the melamine resin modified with the glycidyl compound according to the present invention is that it is not destroyed by compressive force. Thermosetting resins generally have low compressive strength and are easily broken, but the melamine resin modified with the glycidyl compound according to the present invention absorbs compressive energy by deforming itself in response to compressive force.
It is thought that destruction can be prevented.

Dog MJILL' Solid melamine tree prepared in "Examples 3 to 6" @2100
900 parts by weight of pulp, 20 parts by weight of zinc stearate as a mold release agent, 0 parts by weight of 7-talic anhydride as a hardening agent.
．． 4 parts by weight was added and put into a pot mill, and the mixture was rotated for 3 hours to obtain a powdery melamine resin molding material.

This melamine resin molding material is molded into 1 piece using a 37t press molding machine.
Molded at 65℃ for 2 minutes, diameter is 50m+e, thickness is 0.8 arm, 1.6 arm, 3.
A 2 mm disk was created. The DuPont impact strength of each disc was measured. For comparison, similar disks were prepared for the molding material of Comparative Example 1, and the DuPont impact strength was measured. The results are shown in Table 5.

As shown in Table 5, the impact strength of Example 9 using a melamine resin modified with a glycidyl compound was more than double that of Comparative Example 1 using an unmodified conventional melamine resin. It is confirmed that there is. Therefore, even if the wall thickness is reduced to 172mm compared to the conventional one, it is possible to secure the same or higher impact strength, and it becomes possible to mold thin-walled tableware and the like.

Solid melamine resin 2700 prepared in W Nihong “Examples 3 to 6”
300 parts by weight of pulp, 20 parts by weight of zinc stearate as a mold release agent, 0 parts by weight of 7-talic anhydride as a hardening agent.
．． 4 parts by weight was added and put into a bot mill and rotated for 3 hours to obtain a powdery melamine resin molding material.

This melamine resin molding material conforms to JIS K 6911.
A test piece was prepared by molding with an injection molding machine in accordance with the above, and its Charpy impact strength and compressive strength were measured.

! For comparison, a test piece was similarly prepared using thermoplastic resin PP5 (polyphenylene sulfide) and measurements were conducted (Comparative Example 4). The results are shown in Table tA6.

As shown in Table 6, Example 10, which uses a glycityur compound-modified melamine resin, has the same impact strength and compressive strength as Comparative Example 4, which is a thermoplastic resin such as PPS known as ennonearing plastic. Therefore, it is possible to expand the application to the field of thermoplastic resins, which was previously impossible to use with thermosetting resins, such as structural parts such as casters.

[Effect of the Invention J As described above, in the present invention, melamine tM1! 'I
By modifying t with a glycidyl compound, the flexibility of the melamine resin can be increased, and the impact resistance, crack resistance, dimensional stability, etc. can be improved.

Claims (3)

[Claims] (1) A melamine resin obtained by reacting melamine and formaldehyde, which is characterized by being modified with a glycidyl compound. (2) A method for producing a melamine resin, which comprises reacting melamine and a glycidyl compound, and then reacting the reactant with formaldehyde. (3) A melamine resin molding material comprising a base material and a melamine resin modified with a glycidyl compound.