JP3289970B2 - Reactive diluent for thermosetting resin and thermosetting resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reactive diluent for thermosetting resins and a thermosetting resin composition containing the same.

[0002]

2. Description of the Related Art Thermosetting resin compositions contain plasticizers such as dioctyl phthalate, dibutyl phthalate, and succinate to improve workability. These additives are prevented from falling off and volatilizing. At the same time, a reactive diluent such as butyl glycidyl ether, polyethylene glycol, diglycidyl ether or the like is added to reduce the viscosity and improve the workability.

[0003] However, the reactive diluents as described above have not been sufficient as reactive diluents because of their relatively high viscosity and low solubility. In addition, among the reactive diluents, butyl glycidyl ether, which has been widely used, has been pointed out to have an adverse effect on the human body, and is becoming difficult to use. On the other hand, benzyl alcohol has been proposed as an alternative, but it has a bad smell and has poor reactivity with the reactive group of the thermosetting resin, so that unreacted benzyl alcohol is contained in the cured resin. Residue in a large amount, the mechanical strength decreases, and this volatilizes later, causing dimensional changes such as thinning and shrinkage of the resin,
Not very good.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a low-viscosity, high-solubility, almost odorless, no adverse effect on the human body, The thermosetting resin has good reactivity with the reactive group of the thermosetting resin when mixed with the curable resin, and can obtain a thermosetting resin composition having excellent mechanical strength and dimensional stability. It is an object of the present invention to provide a reactive diluent for resins and a thermosetting resin composition having excellent mechanical strength and thermal stability.

[0005]

To achieve the above object, the present invention has the following constitution. That is, the reactive diluent for a thermosetting resin of the present invention is used for an epoxy resin or a polyurethane, and has the following general formula

Embedded image (Wherein, R is a methyl group or an ethyl group, m is 1-3, n
Is 1 to 2 and the position of the substituent is not limited), or an alkylnaphthalene compound represented by the formula (1) or a mixture of two or more thereof. Further, the thermosetting resin composition of the present invention comprises 97 to 60% by weight of a thermosetting resin composed of an epoxy resin or polyurethane and 3 to 40% by weight of the reactive diluent.

The above-mentioned alkylnaphthalene compounds, ie, those in which one or two isopropyl groups are added to one or three methyl or ethyl groups added to the naphthalene ring, include methyl isopropyl naphthalene, dimethyl isopropyl naphthalene, Trimethyl isopropyl naphthalene, methyl diisopropyl naphthalene, dimethyl diisopropyl naphthalene, trimethyl diisopropyl naphthalene, ethyl isopropyl naphthalene, diethyl isopropyl naphthalene, triethyl isopropyl naphthalene, ethyl diisopropyl naphthalene, diethyl diisopropyl naphthalene, triethyl diisopropyl naphthalene, methyl ethyl isopropyl naphthalene, dimethyl ethyl isopropyl naphthalene, Methyl diethyl isopropyl naphthalene Methyl ethyl diisopropyl naphthalene, dimethyl ethyl diisopropyl naphthalene, include methyl diethyl diisopropyl naphthalene, in these compounds, a methyl group, an ethyl group, an isopropyl group may be added to any position on the naphthalene ring. These alkylnaphthalene compounds may be used alone or in a mixture of two or more.

The present invention uses the above alkylnaphthalene compound as an active ingredient of a reactive diluent.
There is no particular problem even if other organic compounds such as benzene, naphthalene, indane, indene, or a compound in which an alkyl group or the like is added to these rings are mixed in the reactive diluent. However, for the remarkable effect of the present invention, the alkylnaphthalene compound is contained in the reactive diluent.
Preferably, it is contained in an amount of 50% by weight or more.

The alkylnaphthalene compound according to the present invention is obtained by separating and recovering methylnaphthalene, dimethylnaphthalene, ethylnaphthalene and the like contained in a product oil obtained by catalytically modifying a naphtha or kerosene fraction by a distillation operation or the like, and separating them by propylation. Thus, it can be easily obtained.

The reactive diluent of the present invention comprises an epoxy resin,
Can be used for polyurethane.

The alkylnaphthalene compound represented by the above formula (2) exerts its effect when added to the thermosetting resin in an amount of 3% by weight or more, and requires 40% by weight to maintain the mechanical properties of the cured product at a certain level or more. % Or less is preferable.

A resin composition comprising a reactive diluent for a thermosetting resin and a thermosetting resin is suitably used for paints, adhesives, coating materials, cast products, molded products or laminated products.

The alkylnaphthalene compound of the present invention has a high dissolving power because of the naphthalene ring. Further, it has a low boiling point at around 300 ° C. and is not easily volatilized, and has sufficient reactivity with the reactive group of the thermosetting resin. For example, in an epoxy resin composition or a polyurethane composition, it is presumed that a reaction as schematically shown by the following formula 1 occurs.

(Equation 1)

That is, the alkylnaphthalene compound is first oxidized, and the tertiary carbon of the isopropyl group becomes a radical. Then, in the epoxy resin composition, it reacts with an unreacted epoxy group to form an ether bond, and in the polyurethane composition, reacts with an unreacted isocyanate group to form a urea bond and stabilize.

As described above, since the reactive diluent of the present invention contains the above-described alkylnaphthalene compound as an active ingredient, the thermosetting resin has a large dissolving power and good compatibility.
It is easy to dilute, and oxidizes to combine with the reactive group of the thermosetting resin to become non-volatile and has a high boiling point, so that it is difficult to volatilize, and to improve the mechanical strength and stability of the cured resin, It does not cause dimensional change, bleeding, etc. due to thinning, shrinkage, etc. of the curable resin. In addition, since it consumes oxygen in the reaction process and lowers the oxygen concentration in the resin, it also has an antioxidant effect on the resin composition. Further, since the viscosity is low, the diluting property with respect to solid components such as talc, calcium carbonate and pigment is also good, and these can be mixed in a large amount.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on Embodiments 1 to 3. Example 1 A raw material fraction having the composition shown in the center column of Table 1 was propylated, a fraction having a boiling point range of 290 to 310 ° C. was separated and recovered by distillation, and propyl having a composition shown in the right column of Table 1 was collected. An oil was obtained.

[0016]

[Table 1]

This solvent (reactive diluent) has no naphthalene odor and has a viscosity of 7.5 centistokes (30
° C). Further, it was found that this solvent did not cause a bleeding phenomenon (visually) with the thermosetting resin and had a very high compatibility.

Example 2 An example of application to an epoxy resin will be described. The epoxy resin composition containing the reactive diluent (propylated oil) obtained in Example 1 was mixed at the compounding ratio shown in Table 2 (Example) and cured at room temperature to obtain a cured product. A cured product was obtained in the same manner also for an epoxy resin composition containing no propylated oil (Comparative Example).

[0019]

[Table 2]

A boiling water test and an accelerated weather resistance test were performed on both of these cured products. Boiling water test is 3cm x 15
The test specimen of cm was immersed in water at 100 ° C. for 24 hours, and the ratio of the expansion coefficient before and after the immersion was measured to calculate the rate of change.

The accelerated weathering test was performed using a sunshine weatherometer under the conditions of 40 ° C. and 100% relative humidity, and the elapsed time when the strength deteriorated by 50% was shown in Table 2. The test pieces according to the examples after both tests did not show any thinning, shrinkage, etc., and did not cause bleeding or the like. On the other hand, the test piece according to the comparative example showed severe shrinkage and bleeding.

As a result, it is understood that the resin composition containing the reactive diluent of the present invention is excellent in deterioration resistance, weather resistance, dimensional stability, heat stability and the like. The compositions of the examples can be suitably used as cast products, molded products or laminated products.

Example 3 An example of application to polyurethane is shown. The polyurethane composition containing the reactive diluent (propylated oil) obtained in Example 1 was mixed at the compounding ratio shown in Table 3 (Example), and the mixture was applied on an aluminum test plate, and the thickness was 0.1 mm. A coated film was formed. In addition, a coating film was formed in the same manner for a urethane resin composition containing no propylated oil (Comparative Example).

[0024]

[Table 3]

Twenty-four hours after the application, both of the coating film forming plates were placed in 10% sulfuric acid at room temperature, heating was started, and the sulfuric acid temperature (peeling temperature) at the start of peeling of the coating film was measured. , And Table 3. As a result, it is understood that the resin composition containing the reactive diluent of the present invention is excellent in heat resistance and acidity. The compositions of the examples can be suitably used as rust preventive paints, coating materials and the like.

[0026]

The reactive diluent for thermosetting resins of the present invention has a low viscosity, a high solubility and is almost odorless.
Since it is difficult to volatilize and has no adverse effect on the human body, it is very excellent in handling, blending design, working environment and safety. Furthermore, because of its low viscosity, it has good dilutability with respect to solid components such as talc, calcium carbonate, pigments, etc., and can be mixed in large amounts and can be applied to various uses.

In addition, when this diluent is mixed with the thermosetting resin, the stability of the mixture is good because of high compatibility, and the unreacted material is hardly formed because of good reactivity with the reactive group of the thermosetting resin. In addition, since oxygen is consumed in the reaction process in addition, the cured product is excellent in dimensional stability and antioxidant properties. Thus, the present composition is rich in mechanical strength and chemical stability, and has great industrial applicability.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kota Sugihara 2-10-1, Toranomon, Minato-ku, Tokyo Nippon Petrochemical Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 1 / 00-101/16 C08G 18/30 C08G 59/40

Claims (2)

(57) [Claims] [Claim 1] The following general formula: (Wherein, R is a methyl or ethyl group, m is 1-3, n is 1-2 , and the position of the substituent does not matter), or a mixture of two or more alkylnaphthalene compounds .
As an active ingredient, for epoxy resin or polyurethane
Reactive diluents for thermally curable resin needed. 2. An epoxy resin or a polyurethane.
A thermosetting resin composition comprising 97 to 60% by weight of a thermosetting resin and 3 to 40% by weight of a reactive diluent for a thermosetting resin according to claim 1.