JPH0488048A - Production of highly heat-resistant resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a cured polybutadiene product with high heat resistance.

More specifically, the present invention relates to a method for producing a cured polybutadiene product having a high degree of heat resistance and suitable as a structural material for aircraft fuselages and automobile outer panels, resin parts for electronic devices, and the like.

(Prior Art) When polybutadiene is cured by a method such as radical curing, a rubber-like or resin-like cured product is obtained.

Polybutadiene is usually cured at a temperature of 100 to 140°C, and is widely used in industry as a backing material, sealant, adhesive, etc. depending on the hardness of the cured product.

(Problems to be Solved by the Invention) However, the cured polybutadiene products obtained by conventional techniques have a major drawback of low heat resistance. The heat resistance of a resin is evaluated based on its thermal deformation humidity (hereinafter abbreviated as HDT), and HDT of 100° C. or higher is required for resins used for aircraft fuselages, automobile outer panels, and the like. However, conventional polybutadiene cured products have an HDT of 5
Since the temperature is below 0°C, expensive so-called engineering plastics such as polycarbonate and polyphenylene oxide are currently used exclusively for the above-mentioned applications.

However, polybutadiene is a relatively inexpensive material, so if it is possible to obtain a hardened HDT of 100°C or higher from polybutadiene, it will become possible to replace engineering plastics, which would have great commercial significance. . For this reason, the industry is currently interested in obtaining cured polybutadiene products with an HD of 7100° C. or higher.

An object of the present invention is to provide a method for producing HDT cured products of 100°C or higher from polybutadiene.

(Means for Solving the Problems) As a result of intensive study by the inventors on a method for curing polybutadiene, surprisingly, by heating and curing polybutadiene at a temperature of HtO°C or higher, a cured product of conventional polybutadiene could be cured. It was discovered that a cured product with an H D T of 100° C. or higher, which has dramatically improved heat resistance to an extent impossible to achieve, was obtained, and the present invention was completed.

That is, the method for producing a highly heat-resistant resin according to the present invention is characterized in that polybutadiene is cured at a temperature of 180° C. or higher.

Polybutadiene used in the present invention is synthesized by polymerizing butadiene by various methods. As a polymerization method, for example, N
Examples include anionic polymerization using a dispersion or an organic alkali metal compound as a catalyst, radical polymerization using an organic peroxide as a catalyst, cationic polymerization using a free-solat fluorine type catalyst, and coordination anionic polymerization using a Ziegler type catalyst.

It is.

Furthermore, as the raw material polybutadiene of the present invention, a copolymer in which a monomer other than butadiene units is introduced into the polymer chain can also be used.

Examples of the comonomer include styrene, α-methylstyrene, acrylonitrile, and the like, with styrene being the most preferred.

Therefore, the raw material polybutadiene in the present invention includes not only butadiene homopolymers, but also modified polybutadiene and butadiene copolymers.

Radical curing, cationic curing, anionic curing, etc. can be used to cure the raw material polybutadiene.
Among these, the curing method that can be preferably used is radical curing. Radical curing can be carried out in the presence of a small amount of air (1 d).

And it is preferable to carry out in the presence of a radical initiator. Examples of radical initiators include methyl ethyl ketone peroxide, 1,1-bis(t-butylperoxy)
3.3.5-) Limethylcyclohexane and t-butylhydroperoxypolybutadiene contain main chain type (trans and nce) double bonds in addition to vinyl type double bonds. In the present invention, there is no particular restriction on the type of double bond in the raw material polybutadiene, but vinyl type double bonds are usually used.
A polybutadiene containing at least mol %, preferably at least 20 mol %, particularly preferably at least 40 mol %, and most preferably at least 60 mol % is suitable as the raw material polybutadiene.

The number average molecular weight of the raw material polybutadiene is -50 on the membrane surface.
It is in the range of 0 to 150,000, preferably 1,000 to 20,000, particularly preferably 1,500 to 8,000. Number average molecular weight is 5
If it is less than 00, the curing speed will be slow, and if it is more than 150,000, the viscosity during molding will increase and it will be difficult to handle.

In the present invention, if necessary, the raw material polybutadiene can be modified in advance with an acid, peroxide, etc. to introduce a hydroxyl group or a carboxyl group. For example, a polymer obtained by adding maleic anhydride to polybutadiene or a polymer obtained by epoxidizing double bonds between carbons can be used as the raw material polybutadiene in the present invention.
Organic peroxides such as di(t-butylperoxy)hexyne-3, 2,3-dimethyl-2,3-diphenylbutane,
Aromatic hydrocarbons such as 2,3-diethyl-2,3-diethylbutane are commonly used. Among these, initiators that can be preferably used include 2,5-(t-butylperoxy)hexyne-3,23-dimethyl-2,3-diphenylbutane and 2゜3-diethyl-2,3-diethylbutane. can be mentioned. Furthermore, if necessary, two or more of these initiators can be used in combination.

These initiators can be used in an amount of usually 0.1 to 10 parts by weight, preferably 0.05 to 2 parts by weight, based on 100 parts by weight of polybutadiene.

The heating temperature required for curing in the present invention is 180°C or higher, preferably 200 to 500°C, particularly preferably 210°C.
-400°C1, most preferably 220-300°C. In addition, in the present invention, HDT of the cured product
It is sufficient if the temperature is 100°C or higher, especially for high HDT
(for example, 200°C or higher), the heating temperature is 180 to 240°C, preferably 200 to 230°C.
°C is sufficient. If the temperature is lower than 180°C, the HDT of the resulting cured product will be extremely low and the effects of the present invention will not be exhibited.

The time required for curing varies depending on the heating temperature, but is usually 1
The time period is from 0 seconds to 10 hours, preferably from 30 seconds to 5 hours, particularly preferably from 1 minute to 4 hours, and most preferably from 3 minutes to 3 hours.

Heating does not necessarily require a solvent, but it can also be carried out in the presence of a solvent or plasticizer that does not vaporize at the heating temperature.

Further, prior to the above heating, the cured product of the present invention can also be obtained by heating the raw material polybutadiene in advance at a temperature lower than 180°C to make a semi-cured product, and then heating it at 180°C or higher, if necessary. .

In addition, when heating, a part of polymer or monomer other than the raw material polybutadiene of the present invention may be mixed as necessary within a range that does not impede the effects of the present invention. Examples of the fibrous filler that can be mixed with the polymer include carbon fiber, glass fiber, potassium titanate fiber, ceramic fiber, and metal carbide fiber. These inorganic fillers are the raw material polybutadiene 1 of the present invention.
It can be used in a range of 0 to 200 parts by weight per 00 parts by weight.

Since the cured product obtained by the method of the present invention has a high degree of heat resistance, it is suitable for use as a structural polishing material for aircraft bodies, automobile outer panels, etc., resin parts for electronic devices, and the like.

(Effects of the Invention) As shown in the following examples, by curing raw material polybutadiene by the method of the present invention, a cured product with extremely high heat resistance of HDT of 100° C. or higher can be obtained.

This high heat resistance is a surprising effect that cannot be expected from conventional cured polybutadiene products.

(Example) The present invention will be specifically explained below using Examples, but the present invention is not limited thereto.

Examples include natural rubber, chloroprene rubber, polymethyl methacrylate, and polystyrene.

Examples of the monomers that can be mixed include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, triallyl isocyanurate, and triallyl cyanurate.

It is desirable to use these polymers and monomers in an amount of 10 parts by weight or less based on 100 parts by weight of the raw material polybutadiene of the present invention.

Furthermore, an inorganic filler can be added to the raw material polybutadiene of the present invention, if necessary.

Inorganic fillers that can be used include various powder fillers, fibrous fillers, spherical fillers, and the like. Examples of powdered fillers include metal oxides such as iron oxide, alumina, and magnesium oxide; aluminum hydroxide, magnesium hydroxide,
Examples include hydrated metal oxides such as calcium hydroxide; carbonates such as carbonate; silicates such as talc and clay.

Example 1 Liquid polybutadiene with number average molecular weight fa3000 and vinyl type double bond or 65 mol% (Nisseki Polybutadiene B-3000 from Nisseki Chemical Co., Ltd., viscosity 500 poise at 25°C) 10
A hardening raw material was prepared by adding 1.0 parts by weight of 2,5-di(t-butylperoxy)hexyne-3 to 0 parts by weight, and heating and stirring the mixture at 60°C.

After pouring this hardening raw material into a brass mold, the temperature reaches 18
Place the mold in an oil bath controlled at 0°C. A and held for 2 hours to harden. The heat distortion temperature of the obtained molded product was measured using a heat distortion tester HD- manufactured by Ajiyasuda Seiki Seisakusho.
When measured using a 500-PC under a load of 18.5 kg/c, a high value of 110°C was obtained.

Example 2 Liquid polybutadiene with number average molecular fit 2000 and 65 mol% vinyl double bonds (Nisseki Polybutadiene B-2000, manufactured by Nisseki Chemical Co., Ltd., viscosity 150 poise at 25°C)
A hardening raw material was prepared by adding 10 parts by weight of 2,3-dimethyl-2,3-diphenylbutane to 100 parts by weight and heating and stirring the mixture at 80°C. After pouring this hardening raw material into a brass mold, the mold was immersed in an oil bath whose temperature was controlled at 240° C., and was held for 2 hours to harden.

When the heat distortion temperature of the obtained molded product was measured in the same manner as in Example 1, it was found to be a very high value of 143°C.

Comparative Example 1 The same procedure as in Example 2 was conducted except that the raw materials of Example 2 were used and the curing was performed at 140°C. The heat distortion temperature was a very low value of 48°C.

Claims (1)

[Claims] 1. A method for producing a highly heat-resistant resin, which comprises curing polybutadiene at a temperature of 180° C. or higher.