JP3341852B2 - Synthetic resin composition and molded article obtained by curing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a curable resin composition.

[0002]

2. Description of the Related Art US Pat. No. 4,200,706 describes a curable composition comprising a novolak type phenolic resin and divinylbenzene.

[0003] The present inventor has prepared the above compositions based on the above specification, but found that they were separated and could not be mixed uniformly.

[0004] When searching for a novolak-type phenolic resin having excellent compatibility with divinylbenzene, it has already been found that a novolak-type phenolic resin having a specifically high ortho / para ratio is suitable.

[0005]

However, a curable resin composition comprising a novolak-type phenolic resin having a high ortho / para ratio and divinylbenzene has a disadvantage that the heat resistance of the cured product is insufficient. .

[0006]

Means for Solving the Problems Accordingly, the present inventors have conducted intensive studies in view of the above situation. As a result, when a phenol-dicyclopentadiene-based resin is used as a novolak-type aromatic hydrocarbon-formaldehyde resin, the curable resin is cured. It has been found that the heat resistance of the product is remarkably improved, and the present invention has been completed.

That is, the present invention relates to a novolak type aromatic hydrocarbon-formaldehyde resin (A) and divinylbenzene
Emissions such (B), and in the curable resin composition of the heat curing accelerator as essential components, wherein the resin (A), the phenol - curable resin characterized by using the di-cycloalkadienyl diene-based resin composition It provides things.

In the present invention, the phenol-dicycloalkadiene resin refers to a synthetic resin comprising a polymer obtained by polymerizing phenols and dicycloalkadiene as essential components. Hereinafter, the phenol-dicycloalkadiene-based resin is simply referred to as resin (A).

The resin (A) used in the present invention may have any molecular weight and is not particularly limited, but preferably has a number average molecular weight of 200 to 2,000, and particularly preferably has a number average molecular weight of 400 to 1,000. Particularly preferred.

The production method of the resin (A) is not particularly limited. For example, the resin (A) can be easily obtained by reacting a dicycloalkadiene with a phenol in the presence of a catalyst if necessary. it can.

As the phenols used in the production of the resin (A), any known and commonly used phenols can be used.
For example, phenol, bisphenol F, bisphenol A, bisphenols such as bisphenol AF, ortho-cresol, meta-cresol, alkyl-substituted phenols such as P-tert-butylphenol, halogenophenols such as bromophenol, and phenolic hydroxyl groups such as resorcinol. Examples thereof include aromatic hydrocarbons containing two or more naphthols such as 1-naphthol, 2-naphthol, 1,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene. These phenols may be used alone or in combination of two or more.

On the other hand, examples of the dicycloalkadiene include dicyclopentadiene. The catalyst for obtaining the resin (A) is not particularly limited, and examples thereof include Lewis acid catalysts such as aluminum chloride, boron trifluoride, zinc chloride, sulfuric acid, and titanium chloride.

In order to obtain the resin (A), for example, a phenol is heated and melted, a catalyst is usually added, and a dicycloalkadiene is added thereto to carry out a reaction.

The reaction ratio between the dicycloalkadiene and the phenol is usually from 1: 0.05 to 1: 15.0 (molar ratio), and the reaction time is usually from 1 to 24 hours. The product thus obtained may be used as the resin (A) as it is, but it is better to distill off unreacted phenols and dicycloalkadiene by distillation under reduced pressure, etc. The cured product has better heat resistance.

In producing the resin (A), furfural, urea, melamine, acetoguanamine, benzoguanamine and the like may be used in combination with phenols, if necessary. Further, a co-condensation may be performed by adding a formaldehyde supply source such as paraformaldehyde.
The above reaction may be performed in the presence of an organic solvent, or an organic solvent may be added to the obtained reaction product. The organic solvent used at this time is not particularly limited, and examples thereof include nitrobenzene and carbon disulfide. The above reaction may be carried out in a batch kettle or may be carried out in a tubular reactor having a static mixing element. The resin (A) may be used alone, but it is also possible to use a mixture of several different types.

The divinyl benzene (B) in the present invention, the rack
Any known crosslinking agent can be used as the crosslinking agent . Examples thereof include divinylbenzene, alkyldivinylbenzene, and halogen-substituted products. Divinylbenzene is most preferable in consideration of reactivity and workability. In addition, the divinylbenzenes (B) used in the present invention can be used singly, in a mixture of two or more, and further containing other third components.

Other third components in this case include, for example, aromatic monovinyl compounds such as styrene, methylstyrene, ethylstyrene and monobromostyrene, methyl (meth) acrylate, stearyl (meth) acrylate, ( Examples thereof include aliphatic monovinyl compounds such as (meth) acrylic acid, N-methylol (meth) acrylamide, and γ-mercaptopropyltrimethoxysilane.
Among them, these third components can be used alone or in combination of two or more. Preferably, those having high purity of divinylbenzenes are used.

The mixing ratio of the components (A) and (B) in preparing the synthetic resin composition of the present invention is not particularly limited, and the resin (A) used and the divinylbenzenes (B) are not particularly limited. Resin (A)
The total number of reactive bonds of the methylene group and the unsaturated double bond of divinylbenzenes in the resin (A) is made equal to or less than the number of bonds of the aromatic ring skeleton, that is, the phenolic skeleton in the resin. Preferably, it is in the range of 1 equivalent to 0.8 equivalent.

Since the resin (A) is a phenolic substance acting as a polymerization inhibitor, the resin (A) and the divinylbenzenes (B) can be mixed at room temperature or under heating. However, in consideration of safety, it is preferable to mix at as close to normal temperature as possible.

If there is no problem even if a solvent is contained in the final use method, a solvent can be added if necessary. In the synthetic resin composition of the present invention, after synthesizing the resin (A), the divinylbenzenes (B) may be mixed immediately in the same reactor, or the synthesized resin (A) may be once taken out of the reactor. Then, the resin (A) and the divinylbenzenes (B) may be newly mixed in a separate container.

The reaction when the divinylbenzenes (B) act as a crosslinking agent for the resin (A) is a reaction in which a double bond is added to an aromatic nucleus.

Examples of the curing accelerator used in the synthetic resin composition of the present invention include metal chlorides such as aluminum chloride and stannous chloride, inorganic acids such as sulfuric acid, hydrochloric acid and phosphoric acid, benzenesulfonic acid, and paratoluene. Organic sulfonic acids such as sulfonic acid, acetic acid, oxalic acid, organic carboxylic acids such as maleic acid, as well as sulfonates derived from resin (A), phosphites such as phosphorous monophenyl, sulfuric acid, Esters derived from organic sulfonic acids, for example, latent catalysts represented by salts such as methyl p-toluenesulfonate and ammonium chloride, that is, those which decompose at a certain temperature to generate acidic components No. These curing accelerators may be used alone or in combination of two or more.

Also, not only the above-mentioned curing accelerators but also their halides, for example, aromatic sulfonic acids such as bromophenolsulfonic acid, fluorophenolsulfonic acid, trifluoromethylphenolsulfonic acid, etc. It is also possible to use a compound in which a hydrogen atom is substituted with a halogen atom or an atomic group having a halogen atom, or a compound in which a hydrogen atom in an alkyl group such as trifluoromethylcarboxylic acid or monobromoacetic acid is substituted with a halogen atom.

As the curing accelerator, an organic sulfonic acid is preferable because a uniform solution can be easily obtained and the curing speed can be easily adjusted. The amount of the curing accelerator used is not limited, but may be 0.1 to 100 parts by weight of the crosslinking agent.
-5 parts by weight is preferred. It is also effective in some cases to use a mixture of the above-mentioned ordinary curing accelerator and a latent catalyst.

The curing time of the synthetic resin composition of the present invention depends on the type of the resin (A) and the divinylbenzenes (B) used,
Since the ratio varies depending on the mixing ratio and the type and amount of the curing accelerator, it is preferable to appropriately mix and cure and then select the optimal conditions after curing.

When an organic sulfonic acid such as benzenesulfonic acid or paratoluenesulfonic acid is used as the above-mentioned curing accelerator, the organic sulfonic acid may be used, for example, in the case of the above-mentioned phenols used for producing the resin (A). It is preferable that the composition is dissolved and used in a diluted state, because the composition can be uniformly cured without locally generating gel.

It is essential to use the resin (A) for the synthetic resin composition of the present invention. If necessary, a novolak type phenol resin, a resol type phenol resin, an epoxy vinyl ester resin, an unsaturated polyester resin, etc. May be used in combination with the curable resin. Hexamethylenetetramine may be used in combination with divinylbenzenes (B) as a crosslinking agent .

US Pat. No. 4,200,706 discloses that
Although a curable composition comprising a novolak type phenol resin and divinylbenzene is described, the composition of the present invention has remarkably improved heat resistance of a cured product by selectively using the resin component.

The synthetic resin composition of the present invention is further excellent in mixing solubility of the resin (A) and the divinylbenzenes (B), so that it can be handled as a stable solution as compared with a dispersion. It is possible to cure uniformly without generating gas and at room temperature.

As described above, the synthetic resin composition of the present invention has excellent mixing stability and can be uniformly cured, and thus has the advantages of phenolic resin such as flame retardancy, low smoke generation, heat resistance, strength and the like. It also solves the drawbacks of workability, curability, moldability, shrinkage, distortion, color tone, and the like. The synthetic resin composition of the present invention can be used not only by curing the synthetic resin composition alone, but also by curing together with a known and commonly used reinforcing material and filler, which is useful for various applications. Become.

The resin composition obtained by the present invention includes, for example, various molding materials, curable resin prepreg, glass fiber sizing agent, binder for molding sand, binder for grinding wheel, adhesive, binder for friction material , Refractory binders, filter binders, thermal insulator binders, semiconductor encapsulation materials, electrical insulation laminates, foam materials, resin concrete, rubber reinforcing agents,
It can be used not only in fields where novolak resins have been used conventionally, such as paints and coatings for various applications, but also in fields where resole-type phenolic resins and unsaturated polyester resins have been used, improving performance. That is what you can expect.

The synthetic resin composition of the present invention may be cured alone, or it may be crosslinked and cured by compounding with a reinforcing material or a filler, and then molded. The molding method is not particularly limited, and for example, a method such as prepreg lamination compression molding, injection molding, RIM (reactive injection molding), SMC, hand lay-up, and pultrusion molding can be employed. .

[0033]

The present invention will be described below in more detail with reference to Synthesis Examples and Examples. All parts and percentages in the examples are on a weight basis.

Example 1 Phenol-dicyclopentadiene resin DPP-60
A mixture of 80 parts of divinylbenzene as a cross-linking agent and 20 parts of ethylstyrene was dissolved at 50 ° C. in 100 parts of 0M [manufactured by Nippon Oil Co., Ltd., number average molecular weight: 465, raw material phenol was phenol]. , Viscosity 380cps
(25 ° C.) to give a homogeneous red-brown solution. 0.9 parts of xylene sulfonic acid was added to this composition, and the composition was heated and crosslinked at 100 ° C. for 1 hour to obtain a cured product.

With respect to this cured product, the bending strength (JIS
K-6911), heat distortion temperature (ASTM D648),
The glass transition temperature Tg (using DMA) was measured. The measurement results are shown in Table 1.

Example 2 Phenol-dicyclopentadiene resin: DPP-6
A mixture of 64 parts of divinylbenzene as a crosslinking agent and 16 parts of ethylstyrene was dissolved at 50 ° C. in 100 parts of 00H (manufactured by Nippon Oil Co., Ltd., number average molecular weight: 580, raw material phenol was phenol). , Viscosity 520cps
(25 ° C.) to give a homogeneous red-brown solution. 0.9 parts of xylene sulfonic acid was added to this composition, and the composition was heated and crosslinked at 100 ° C. for 1 hour to obtain a cured product.

The cured product was measured for flexural strength, heat distortion temperature and Tg in the same manner as in Example 1. The measurement results are shown in Table 1.

Comparative Example 1 In a four-necked 3-liter flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, 940 g of phenol (1
0 mol), 470 g of xylene and 281.3 g (7.5 mol) of 80% paraformaldehyde were added and stirring was started. As a catalyst, 4.7 g of zinc acetate dihydrate was added, and the temperature was raised to the reflux temperature. After distilling xylene and water for 4 hours and reacting while removing only the layer of water flowing out, the distillation was started and the temperature was raised to 130 ° C. while removing residual water and xylene as a solvent. And kept at 130 ° C. for 2 hours.

940 g of water was added and the mixture was cooled to 80 ° C., and the stirring was stopped. The separated upper aqueous layer was extracted, and water was further added thereto to wash and separate zinc acetate as a catalyst by the same operation. Thereafter, the resin layer was heated to remove residual moisture, and the temperature was raised to 170 ° C. After partially removing free phenol at 170 ° C. under reduced pressure, it was taken out of the reaction vessel to obtain a solid novolak type phenol resin. When this resin was repeatedly washed with water 10 times, the content of zinc acetate was 0.003 ppm. This was heated again to remove residual moisture to obtain a solid novolak type phenol resin.

A mixture of 64 parts of divinylbenzene as a crosslinking agent and 16 parts of ethylstyrene was dissolved at 50 ° C. with respect to 100 parts of the resin solid content, and the viscosity was 750 cps.
(25 ° C.) to give a homogeneous tan solution. 0.9 parts of xylene sulfonic acid was added to this composition, and the composition was heated and crosslinked at 100 ° C. for 1 hour to obtain a cured product.

The cured product was measured for flexural strength, heat distortion temperature and Tg in the same manner as in Example 1. The measurement results are shown in Table 1.

[0042]

[Table 1]

As can be seen from Table 1, the cured product of Example 1 of the present invention has remarkably superior heat resistance as compared with the cured product of Comparative Example 1 using a high-orthophenol novolak type phenol resin. .

[0044]

According to the present invention, in a system in which a novolak-type aromatic hydrocarbon-formaldehyde resin is cured with divinylbenzenes, a phenol-dicycloalkadiene-based resin is used as a resin component, whereby a high-ortho novolak-type phenol resin is obtained. As compared with the method using, a particularly remarkable effect is obtained in that a cured product having significantly improved heat resistance can be obtained.

Claims (4)

(57) [Claims] 1. A novolak type aromatic hydrocarbon-formaldehyde resin (A) and divinylbenzenes (B)
And a thermosetting accelerator , wherein the resin (A) is a phenol-dicycloalkadiene-based resin. 2. The composition according to claim 1, wherein the phenol-dicycloalkadiene-based resin is a polymer of a phenol and dicyclopentadiene. 3. A divinyl benzenes (B) is The composition of claim 1, wherein divinylbenzene. 4. A molded article obtained by curing the composition according to claim 1.