JPS63264625A - Mold-making resinous material for molding - Google Patents

Abstract

PURPOSE:To improve the dimensional accuracy and the heat resistance of a resin mold as well as its productivity, by blending a main agent comprising as main components an alicyclic epoxy resin, an inorganic powder and a polyol with a curing agent comprising as main components an acid anhydride and a curing accelerator. CONSTITUTION:This resin mold agent for molding is composed of a main agent comprising as main components 20-80wt.% alicyclic epoxy resin (a), 80-20wt.% inorganic powder (b) and 5wt.% or less polyol (c) per 100pts.wt. of the total of the components (a) and (b), and a curing agent comprising as main components 95-99.9wt.% acid anhydride (d) and 0.05-5wt.% curing accelerator (e). As the component (a), 3,4-epoxycyclohexenylmethyl and 3,4-epoxycyclohexane carboxylate are especially preferred. As the polyol, in view of the cost, harmlessness, etc., ethylene glycol and diethylene glycol are preferred.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a resin molding agent for molding.

More specifically, the present invention relates to a resin molding agent for molding using a main ingredient consisting of an alicyclic epoxy resin and an inorganic powder, and a curing agent consisting of an acid anhydride and an alkylamine.

The resin mold for molding created using the resin mold agent of this invention is
It is used for product models such as mechanical parts, jigs related to the models, molds for sheet metal molding, molds for plastic molding, etc.

In particular, the resin mold of this invention is easier to process than the mold made by Kinkure, so it can be used in fields that require frequent model changes, or when it is necessary to prepare a large number of jigs and tools in a short period of time. It can greatly contribute to shortening delivery times, reducing costs, and reducing weight.

(Prior Art) Conventionally, metal molds have generally been used, and manufacturing has been carried out by mechanical work.

This increases production costs, takes longer delivery times, and
Molds made from gold claws had many drawbacks, such as poor workability, difficulty in repair and modification, and difficulty in maintenance during storage.

As a means to solve this problem, resin molds made of bisphenol A type epoxy resin, novolac type epoxy resin, etc. were used, and their production was based on a "duplication" method using a master model.

(Problems to be Solved by the Invention) However, molding agents using these bisphenol A type epoxy resins and novolac type epoxy resins lack fluidity.

In other words, when manufacturing a resin mold, in order to obtain a molded product with good dimensional accuracy, that is, to obtain a resin mold with good two-dimensional accuracy, it is necessary to remove air bubbles in the resin during processing.
Due to the lack of fluidity, it is difficult to defoam, the productivity is poor, and the resulting molded products lack dimensional accuracy.

Second, it has poor heat resistance.

In other words, when used as a mold for injection molding among resin molds, it is necessary to withstand temperatures of about 150°C, but resin molds using the above-mentioned bisphenol A type epoxy resin etc. can withstand high temperatures of about 120 to 150°C. The disadvantage is that it becomes brittle when exposed to

The present inventor completed the present invention as a result of intensive research to solve these problems.

(Creation of the Invention) Second, the present invention consists of ``(a) 20 to 80% by weight of alicyclic epoxy resin, (b) 80 to 20% by weight of inorganic powder, (C) (a) and (b)
), based on a total of 1 part fn100 weight fi, a main ingredient containing not more than 5 parts alcohol and (d) an acid anhydride 95 to 99.9 weight ω% (e)'F
f! A resin molding agent for molding, characterized in that it consists of a curing agent whose main component is a curing accelerator of 0.05 to 5% by weight.

Examples of the alicyclic epoxy resins used as the resin component in the main resin of the molding resin molding agent of the present invention include 3.4 epoxycyclohexenylmethyl, 3.4 epoxycyclohexane rupoxylate, dibenthene dieboxide, vinyl hexene dieboxy Among them, 3.4 epoxycyclohexenylmethyl and 3.4 epoxycyclohexane carboxylate are preferred.

The structural formula of 3,4 epoxycyclohequinane lupoxylate, which is an example of this alicyclic epoxy resin, is as follows.

The amount of these alicyclic epoxy resins used is 20 to 8 in the main resin.
0% by weight, preferably 30-70% by weight.

More preferably, it is 40 to 60%.

If it is less than 20% by weight, the curing shrinkage rate and coefficient of linear expansion will be small, which is preferable, but the strength will decrease due to the small amount of resin a, making it unsuitable.On the other hand, if it is more than 80vff1%, the strength will improve, but the thermal conductivity will decrease. It is not only unsuitable, but also hardness decreases, and the It! 2f! The coefficient of thermal expansion and coefficient of linear expansion become large, making it unsuitable.

Precipitate-free powders that are another component of the main ingredient of the molding resin molding agent of the present invention include asbestos, alumina, attapulgite, kaolin clay, and volcanic ash.

Carbon black, graphite, finely divided silicic acid, calcium silicate, diatomaceous earth, magnesium oxide, titanium oxide, iron oxide, hydroxide magnetic screw shim. Hydroxide/aluminum, slate powder, sericite, quartz powder (flint), fused silica powder, boron nitride, calcium carbonate, magnesium carbonate, talc.

Feldspar powder, molybdenum dioxide, pallite, vermiculite, whiting, mica, waxite clay, gypsum (anhydrous), etc. are used in appropriate combinations depending on the purpose.

The purpose of mixing these inorganic powders is to improve hardness and thermal conductivity and increase specific gravity.

Further, the respective roles of various inorganic powders are as follows.

・Talc, silica T I 02: Hardness shrinkage and fQ+
a; Reduce tension.

・Glass fiber, ceramic: Increases hardness and reduces heavy spear size.

・Carbon: Improves heat resistance and reduces weight.

・Orben: Metal powder and charge! i Improve the dispersion of 1'9J.

etc., and the combinations and blending ratios vary depending on the application.

Also, when adding gold (FEV), be sure to use orben (clay).
A typical example of the usage ratio in this case is as follows.

Metal powder: 15-30 parts Metal powder: 15-20 parts Olben 2-5 or Carbon 15-20 Talc 'JO-10 Talc 20-5 Olben 2-3 (Clay) The total usage a of this inorganic powder is 80-20 in the base material. Weight%
, preferably 30 to 70%, more preferably 60%
~41 parts%.

In order to uniformly disperse these inorganic powders, orben (
(clay) plays an important role, but if too much orben is added, although the dispersion state can be maintained, the viscosity increases and fluidity is lost, causing problems in processes such as defoaming during resin mold production, making it unusable.

Therefore, the rotation speed of the Henschel mixer at the time of mixing the Olben (clay) suspension and the unmodified powder and the epoxy resin are important points.

If the total amount of the inorganic powder used is less than 20%, the resin 1n will be relatively large, so the strength will improve, which is preferable, but the curing shrinkage rate and linear expansion coefficient will increase, and furthermore, the thermal conductivity will decrease. significantly decreased.

Not suitable.

If the proportion of this indestructible powder decreases, not only will the shrinkage rate and coefficient of linear expansion during curing increase, but also the thermal conductivity of the resin mold will decrease, making it difficult to cycle up as a resin mold for injection molding. This is not preferable because it reduces productivity.

On the other hand, if the total usage λ of inorganic powders is more than 80%, the shrinkage rate and coefficient of linear expansion during curing will decrease, which is preferable, but the strength will decrease, which is not preferable.

The particle size of this inorganic powder is 100 to 500 mesh, preferably 200 to 400 mesh, more preferably 30 mesh.
It is around 0 meshes.

If the particle size is larger than 500 mesh, the strength and surface smoothness after molding will be poor, and on the other hand, there is no particular need to make the particle size smaller than 100 mesh.

Examples of polyhydric alcohols contained in the main ingredient of the molding resin molding agent of the present invention include ethylene glycol and diethylene glycol.

Examples include ethylene monoglycol, neopentyl glycol, glycerin, cyclohexanol, 1°6 hexanediol, trimethylpropane, 1°4 butanediol, and pentaerythritol. Among them, ethylene glycol and diethylene glycol are preferred from the viewpoint of cost and harmlessness.

The amount of these polyhydric alcohols used is 0.1 to 5% in the base agent.
%, preferably 0.3 to 4% by weight.

More preferably, it is 0.4 to 3.0% by weight.

If the amount is less than 0.1% by weight, the reaction will not proceed and it will take time to cure.

If it is more than 5.0m0%, hardness cannot be maintained and heat resistance is poor, making it unsuitable as a molding agent.

As the acid anhydride used as a component of the curing agent of the molding resin molding agent of the present invention, methyltetrahydrophthalic anhydride [trade name: HN220
0. Epicron B-570] Methylendomethylenetetrahydrophthalic anhydride [Product name: Kayahard MCr), Methylhimic anhydride M
HAC-P, MHAC-1] Methylbutenyltetrahydrophthalic anhydride [Product name: Y)-1-306] Dodecenyl succinic anhydride, Methylhexahydrophthalic anhydride [Product name: Rikacid MH-700゜Evicron B
-650, HN3500], among which methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc. are preferred.

The usage notification for these acid anhydrides, which are the majority of the components of the curing agent, is calculated based on the ratio of epoxy equivalent a to acid anhydride equivalent, and in terms of weight, the acid anhydride is 20 to 90. Preferably, the proportion of the acid anhydride is 40 to 70 per 100 of the base resin, and more preferably 55 to 65 of the acid anhydride per 100 of the base.

If the layer ratio of acid anhydride is less than 20 to 100 of base material, it not only takes time to cure.

Since it does not harden sufficiently, a constant hardness cannot be maintained, making it unsuitable as a molding agent.On the other hand, if it exceeds 90, although it hardens sufficiently, it becomes brittle, which is undesirable.

A tertiary amine is used as a curing accelerator for accelerating the effect of the curing agent in the molding resin molding agent of the present invention.

There are boric acid esters, Lewis acids, imitazole, etc.
Among them, benzyldimethylamine, trisdimethylaminomethylphenol and the like are preferred.

The amount of these curing accelerators used is 0.05 to 5.0 in the curing agent.
It is expressed in weight percent, preferably 0.1 to 2°0 type can percent.

More preferably, it is 0.1 to 0.5%.

When the amount is less than 0.05% by weight and 1%, the effect of improving the curing speed is small, loss time increases, it takes time to manufacture the mold, and the cost becomes high.

On the other hand, if the amount is more than 1% by weight, the heat generation will be large, the properties will be uneven, the curing speed will be too fast, the pot life will be shortened, and it will not be possible to work with molds.

Furthermore, if the amount of the curing accelerator used is more than 5%, it is not suitable as a molding agent because it not only does not exhibit hardness, but also becomes brittle and loses heat resistance.

Next, a procedure for creating a resin mold using the molding resin molding agent of the present invention will be described.

■First 9. Prepare the item that will be the prototype of the object you want to create and the container that will be the outline of the mold frame.

■Apply a mold release agent to the product that will become the prototype and place it in the container where the mold frame will be made.

■Mix the pre-mixed base agent and curing agent in a predetermined ratio.

■After mixing thoroughly, defoaming the mixture and pouring it into a container where the mold frame will be made.

■ Defoaming is performed again after pouring into the container.

(2) Place the container filled with molding resin into an oven and harden at 80 to 150"C for several hours.

■When the molding agent has hardened, take it out of the oven and check that it has hardened.

■After confirming that it has hardened, remove the original item and place it in the oven again for 5 to 15 minutes at 150 to 160℃.
Let it harden over time.

The present invention will be explained in detail by giving examples below.

Example-1 The main ingredients were mixed to have the following composition.

(a) 3.4 epoxycyclohexane lupoxylate (Daicel Chemical Celloxide 2021) 53.1 wt% as alicyclic epoxy resin (b) Olben (clay) as solid powder 3.5 wt% iron powder
21.2wt% talc
21.2 wt% (C) Ethylene glycol 1.1 vit% as polyhydric alcohol Next, a curing agent was prepared to have the following composition.

(d) Tetrahydrophthalanhydride g as M anhydride 99. 'ht%(HN-
2200) (e) Benzyldiamine as a curing accelerator o, iwt% Mix the above main ingredient and curing agent according to the procedure described above, put it in a container,
Place the whole container in an oven maintained at 100℃,
It was left to harden for a while.

Next, the product was taken out of the oven, the original model was removed, and the product was placed in the oven again and completely cured at 150° C. for 10 hours.

The resin mold taken out of the oven is sufficiently hard.

It had strength and dimensional accuracy.

Example 2 The same procedure as Example 1 was carried out except that diethylene glycol was used instead of the ethylene glycol seedling in Example 1, and a resin mold with sufficient hardness, strength, and dimensional accuracy as in Example 1 was obtained. Ta.

Claims (1)

[Scope of Claims] (a) Alicyclic epoxy resin 20 to 80% by weight (b) Inorganic powder 80 to 20% by weight (c) Polyvalent to 100 parts by weight of the total amount of (a) and (b) It is characterized by consisting of a main component mainly consisting of 5 parts by weight or less of alcohol, (d) an acid anhydride 95 to 99.9% by weight, and (e) a curing agent mainly containing 0.05 to 5% by weight of a curing accelerator. A resin molding agent for molding.