JPS5923570B2 - epoxy resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition, more specifically a cured product having a long pot life and having good physical properties when cured under mild curing conditions, particularly in terms of machinability and surface strength. The present invention relates to an epoxy resin composition that provides an excellent cured product.

The cured product of the composition is a mixture of epoxy resin, micro hollow bodies such as phenol balloons and micro glass hollow bodies, and a hardening agent, and is lightweight and has excellent cutting properties, as well as properties such as wood feel, heat insulation, and soundproofing properties. Therefore, it is well known that it is used for master models, materials for carving and crafts, synthetic wood for furniture materials, insulation materials, buoyancy materials, etc.

In synthetic wood applications, when the cured product is used as a material for a master model, the cured product is machined or manually cut using tools to create parts that are identical to parts such as car doors and bumpers. A master model of the shape is created, and then a female mold for manufacturing automobile parts is created using this master model as a prototype.

Therefore, the cured product must be able to be easily cut by a machine or manually using a tool, have a smooth surface after processing, that is, have good machinability, and have a certain degree of mechanical strength. At the same time, the surface is required to have strength, such as not being easily scratched when it comes into contact with a solid object, and having good abrasion resistance so that the master model can withstand repeated use. Furthermore, it is desirable that not only the physical properties of the cured product but also the usable life of the composition containing several components be sufficient. In other words, normally, when an epoxy resin and a curing agent are mixed, the viscosity increases due to the reaction between the epoxy resin and the curing agent, and eventually it becomes a solid state, but in order to obtain a cured product of the intended shape, the viscosity of the composition must be adjusted. It is essential to fill the compound into a predetermined mold or prepare it into a predetermined shape while the temperature is sufficiently low. When using an epoxy resin composition for a master model, it is necessary to prepare it into a shape somewhat similar to the shape of the master model before curing, and it is desirable that the working time for this is at least 4 hours or more. . Therefore, it is extremely advantageous that the pot life of the composition at room temperature is 4 hours or more. In addition, depending on the type of curing agent used, in order to impart properties characteristic of that curing agent to the cured product, it is necessary to set curing conditions such as curing temperature and curing time depending on the curing agent, but if possible, it is necessary to set curing conditions such as curing temperature and curing time. It is desirable to obtain a cured product having predetermined physical properties by curing at a low temperature, that is, under mild conditions.
Therefore, an epoxy resin composition that has a sufficiently long pot life and provides a cured product with good machinability, mechanical strength, and surface strength when cured under mild conditions is desirable for use in master models. Of course, an epoxy resin composition that meets these requirements is a preferred composition not only for use in master models but also when used in other synthetic wood applications or applications such as heat insulating materials and buoyancy materials. However, none of the conventionally known compositions or methods satisfactorily meet the above requirements.

In other words, if a cured product of a composition in which microhollow bodies are simply blended with an epoxy resin and a curing agent has a density that provides good machinability, that is, 0.6f7/C7lt or less, the cured product will have a density of 0.6f7/C7lt or less. The surface strength, for example, pencil hardness, is soft, below B, and the mechanical strength is also reduced, making it unsatisfactory for synthetic wood applications, especially as a material for master models. Furthermore, Japanese Patent Publication No. 47-48918 describes a method for obtaining a wood-like cured product by curing a composition consisting of an epoxy resin, microscopic hollow glass spheres, a diamide of ethylene diamine and a linear aliphatic carboxylic acid, and a curing agent. However, although this method provides good machinability due to the presence of the diamide, the pencil hardness is still below B and the surface strength is weak.

Furthermore, the proselene oxide adduct of diethylenetriamine used as a curing agent in this publication has a short pot life. Furthermore, JP-A-50130897 describes the use of acid anhydrides as curing agents, but when acid anhydrides are used as curing agents, it is necessary to cure at a high temperature of at least 100°C or higher, and a special heating device is required. However, the energy consumption required for heating is also large. As described above, conventional epoxy resin compositions for synthetic wood applications, particularly for master model applications, do not fully satisfy physical properties of cured products, pot life, curing conditions, etc.

Therefore, an object of the present invention is to provide an epoxy resin composition which has a sufficiently long pot life at room temperature and which can provide a cured product with excellent machinability and surface strength without loss of mechanical strength under mild curing conditions. There is something to do.

Therefore, the present inventor has proposed that an epoxy resin composition comprising a specific polyamine containing one or more units represented by formula (1) in the molecular chain as a curing agent, a micro hollow body, and a curing agent is as described above. The inventors have discovered that this is an epoxy resin composition that satisfies the requirements, leading to the present invention. (In the formula, n is an integer from 1 to 5, and the oxygen atom is bonded only to the carbon atom.

) Therefore, the present invention uses a polyamine containing one or more units represented by the above formula (1) in its molecular chain as a curing agent in an epoxy resin composition comprising an epoxy resin, a microhollow body, and a curing agent. This is an epoxy resin composition characterized by the following.

It is generally known that polyamines are used as curing agents for epoxy resins, and the pot life, curing conditions, and physical properties of the cured product vary depending on the type of polyamine and the content of amine contained in the polyamine. Although it is known that any type of polyamine can change the physical properties of a cured product, especially the physical properties of a cured product containing micro hollow bodies,
In particular, it has not been fully elucidated whether it affects the special property of the surface strength of the cured product. The epoxy resin composition containing micro hollow bodies using the specific polyamine has a long pot life and provides a cured product with excellent machinability and surface strength under mild curing conditions, and the cured product can be used for synthetic wood. The inventors have found that this material is excellent for use as a material, especially for master models. The epoxy resin composition of the present invention has a sufficiently long pot life of 4 hours or more at room temperature, and therefore can be stably filled into molds or adjusted into a predetermined shape before curing, and is gentle. Since a cured product with predetermined physical properties can be obtained under certain conditions, no special heating equipment is required, the energy consumption required for heating is low, and the obtained cured product has a density of 0.6 tons. /Cd or less, it has sufficient mechanical strength and surface strength of pencil hardness F or more, and of course also has good machinability.

The epoxy resin as used in the present invention is generally referred to as an epoxy resin having one or more epoxy groups in one molecule chain, and includes, for example, epihalohydrin such as epichlorohydrin or dihalohydrin such as glycerine dichlorohydrin and 2,2-bis (4-hydroxyphenyl)propane (commonly known as bisphenol-A), 2,4-hydroxydiphenylmethane, bis(2-hydroxyphenyl)
Methane, bis(4-hydroxyphenyl)methane (commonly known as bisphenol F), 1,1-bis(4hydroxyphenyl)ethane, bis(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)methane , resorcinol,
Polyhydric phenols such as hydroquinone and catechol, the above-mentioned nuclear substitutes, and polyhydric phenols such as halides, or ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1●4-
Butanediol, 1,3-butanediol, 1,5-pentanediol, 1,3-pentanediol, 1,6-
Hexanediol, 1,5-hexanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, glycerin, 2-methyl glycerin,
Alkane (C2 to C3O) poly(N2 to 6) alcohols such as pentaerythritol, poly(n-1 to 40) Oxyalkylene glycol,
Hydroxyl-terminated butadiene-acrylonitrile copolymer to polybutadiene glycono, hydrogenated bisphenol-A1 bisphenol-A glycol with ethylene oxide or propylene oxide added, polyhydric alcohol with ethylene oxide or propylene oxide added to phenol-1 volac resin, tallow oil. , whale oil, fish oil; alcohols obtained from animal and vegetable oils such as rice sugar oil and castor oil, and polyglycidyl ethers obtained by reaction with polyhydric alcohols such as their halides and nuclear water additives. , or epihalohydrin or dihalohydrin with oxalic acid, fumaric acid, maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahedral acid /By reaction with polycarboxylic acids such as phthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid or their halides. The resulting polyglycidyl ester, and further 3,4-epoxycyclohexylmethyl 3,4-
Epoxy resins with internal epoxy groups such as epoxycyclohexane carboxylate, ethylene glycol bis(3,4-epoxydihydrodicyclopentadienyl) ether, and terminal epoxy groups such as 3,4-epoxycyclohexylmethyl glycidyl ether. Examples include epoxy resins containing both internal epoxy groups and internal epoxy groups.

Among these epoxy resins, polyglycidyl ethers of polyhydric phenols are preferable, and diglycidyl ethers of bisphenol A1 bisphenol Fll/1-bis(4-hydroxyphenyl)ethane have a viscosity of 15,000 cPS or less at 25°C, Epoxy equivalent 180
Most preferred are epoxy resins of 1 to 200%. The micro hollow bodies of the present invention have a particle size of 40 to 200μ and a specific gravity of 0.2 to 0.47/d, and specifically include borosilicate glass, silica glass, aluminosilicate glass, and soda lime. Glass, micro glass hollow bodies manufactured using lead glass as raw materials, shirasu balloons manufactured using shirasu as raw materials, floating ash collected by flotation method from pulverized coal combustion ash shells, other carbon balloons, phenol balloons Among them, micro glass hollow bodies or phenol balloons obtained by foaming borosilicate glass or silica glass are preferred. ).

In the present invention, the micro hollow bodies are blended in an amount of 30 to 60% by weight, preferably 40 to 50% by weight in the entire composition.

If it is 60% by weight or more, surface strength and mechanical strength will decrease, and if it is 30% by weight or less, machinability will decrease.

The polyamine of the present invention is a polyamine containing one or more units represented by the above formula (1) in its molecular chain.

Specifically, such polyamines include
Polyamine obtained by reacting polyethylene glycol dihalide described in Japanese Patent Publication No. 6423 with an amine having at least two active hydrogen atoms in the nitrogen atom, Japanese Patent Publication No. 12516/1983, Japanese Patent Publication No. 12864/1989, US Patent Polyamine obtained by cyanoethylating and then hydrogenating polyalkylene glycol described in No. 3,306,809, etc., U.S. Pat. No. 2,888,439
Pelkey Patent No. 67, a polyamine obtained by reacting polyalkylene glycol and polyisocyanate, followed by acid treatment and subsequent alkali treatment, as described in
Examples include polyamines obtained by the reaction of polyalkylene glycol and ammonia as described in the specification of No. on average 2 units in one molecule chain
Polyamines containing from 6 to 6 active hydrogen atoms and having an active hydrogen content of 6 to 20 milliequivalents of 17 and a viscosity of 5 to 200 cps at 25° C. are particularly preferred, and particularly polyamines represented by formula (6) are most preferred.

H2NCH(CH3)CH2fOCH2CH(CH3)
-FxNH2([[) (where X is 2 to 4).

) The polyamine of the present invention is preferably blended in an amount such that the amount of active hydrogen contained in the polyamine is % to 1 equivalent per equivalent of epoxy group contained in the epoxy resin used.

The total amount of epoxy resin and polyamine is 40% in the total composition.
It is blended in an amount of from 50 to 70% by weight, preferably from 50 to 60% by weight. If it is 70% by weight or more, the machinability will decrease, and if it is 40% by weight or less, the mechanical strength and surface strength will decrease.

In the present invention, the epoxy resin, microhollow bodies, and polyamine can be mixed using a common mixing device, such as a universal mixer.

After mixing, the composition is filled into a predetermined mold or prepared into a predetermined shape. Since the composition of the present invention has a pot life of 4 hours or more, the above operations can be carried out stably. In the subsequent curing process, 2 to 6
A cured product having predetermined physical properties can be obtained by simply heating for a period of time. If shrinkage due to curing is to be avoided, such as in the master model, a preferable cured product can be obtained by leaving it at room temperature for one day and then curing it at the above temperature and time. In the present invention, in addition to the epoxy resin, micro hollow bodies, and polyamide Z, auxiliary materials such as fillers, lubricants, and diluents are mixed to the extent that they do not impair the lightness, machinability, mechanical strength, and surface strength of the cured product. It's okay to do that.

Additionally, curing accelerators may be used, but should be used in amounts that do not shorten the pot life of the composition by more than 4 hours. Further, polyamines other than the polyamine of the present invention, polyamide amines, etc. may be mixed to the extent that they do not affect the pot life or the physical properties of the cured product.

The cured product obtained from the composition of the present invention has excellent machinability, surface strength, sufficient mechanical strength, and is lightweight, so it is excellent as a material for synthetic wood, especially master models. It is possible to create a master model extremely easily and precisely, and since the surface is strong, it has excellent wear resistance, and the surface is easily scratched even if it comes into contact with a solid object. Therefore, female molds can be repeatedly made and can withstand long-term use.

Of course, it can also be used as furniture material and carving material.
It can also be used as a heat insulator and buoyancy material. By completing the present invention as detailed above, it is possible to provide an epoxy resin composition that has a long pot life and gives a cured product useful as a material for synthetic wood, especially master models, under mild curing conditions. Therefore, the present invention has great industrial value. The present invention will be specifically described below with reference to Examples. Example 1 Epoxy equivalent 190, viscosity at 25°C 140
Diglycidyl ether 100y of bisphenol A, 00cpS, micro glass hollow body made of borosilicate glass (GlassMIC-ROBALLO manufactured by Toyo Soda Co., Ltd.)
After kneading 130 t (using ONOlGlOl) and polyamine A357 in Table 1 for 20 minutes using a Shinagawa mixer, a part of the mixture was placed in a metal mold used to prepare a test piece for bending stress measurement according to JIS K69ll. It was filled, left to stand for one day, and then heated and cured at 60° C. for 4 hours.

Using the obtained test piece, bending stress was measured according to JISK69ll, and using this test piece, density was measured according to JISK69ll, and pencil hardness was measured according to JISK54OO. The surface of the test piece was also observed to see if it was strongly scratched with a thumb nail. Furthermore, the test piece was shaved using a commercially available planer, and the condition of the cut surface was observed to see if it could be easily cut. Separately, the mixture was left in an atmosphere at 25°C for 3
It was observed whether it deformed by pressing it with a finger every 0 minutes, and the pot life was defined as the state in which it no longer deformed.

The above results are shown in Table 2. Example 2 In Example 1, the epoxy resin had an epoxy equivalent of 17
2. The same operation as in Example 1 was performed except that diglycidyl ether of bisphenol F 1007 having a viscosity of 4300 cps at 25°C and polyamine A 397 as the polyamine were used.

The results are shown in Table 2.

Example 3 In Example 1, the epoxy resin had an epoxy equivalent of 1
79, viscosity 3300 cps at 25°C 1.1-
Polyamine A37 as diglycidyl ether of bis(4-hydroxyphenyl)ethane 100y1 polyamine
The same operation as in Example 1 was performed except that y was used.

The results are shown in Table 2. Comparative Examples 1 and 2 The same operations as in Example 1 were carried out except that polyamine B and polyamine C shown in Table 1 were used as polyamines in amounts of 437 and 13y, respectively.

The results are shown in Table 2. τ Comparative Example 3 Polyamine D in Table 1 was used as the polyamine in Example 1.
The same operation as in Example 1 was performed except that 22tl and 20y of ethylene bisstearamide (Armowax ESB-P, manufactured by Lion Armour Co., Ltd.) were added to the composition.

Claims (1)

[Scope of Claims] 1. An epoxy resin composition comprising an epoxy resin, a microhollow body, and a curing agent, wherein a polyamine containing one or more units represented by formula (I) in the molecular chain is used as the curing agent, and 30 to 6 micro hollow bodies in the total composition
An epoxy resin composition comprising 0% by weight. ■OC_nH_2_n■(I) (In the formula, n is an integer from 2 to 5, and the oxygen atom is bonded only to the carbon atom.) 2 The polyamine has formula (I), where n is 2 or 3, contains an average of 2 to 6 units represented by formula (I) in one molecular chain, and has an active hydrogen content of 6 to 20
milliequivalent/g and a viscosity at 25°C of 5 to 20
2. The composition of claim 1, wherein the composition is a polyamine with 0 cps. 3. The composition according to item 1, wherein the epoxy resin is glycidyl ether of polyhydric phenol.