JP3824398B2 - Phenolic resin molding material - Google Patents

Description

なお、ノボラック型フェノール樹脂は、オルソ／パラ結合比０．８、数平均分子量９００のものを使用した。
【００１１】
【発明の効果】
以上の実施例及び比較例から明らかなように、本発明のフェノール樹脂成形材料は、衝撃強度、静的強度のような機械的強度に優れ、自動車、電気・電子分野における金属代替を大幅に促進するものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a phenol resin molding material excellent in mechanical strength such as impact strength and bending strength.
[0002]
[Prior art]
Phenolic resin molding materials are excellent in heat resistance, dimensional stability, moldability, etc., and have been used for a long time in key industries such as automobiles and electrical / electronics. In particular, since replacement of metal parts with high-strength phenolic resin products reinforced with glass fibers enables a significant cost reduction, active alternative studies are being conducted. However, even for high-strength phenolic resin molding materials reinforced with glass fibers, the Charpy impact strength is about 5 KJ / m ² and the bending strength is about 200 MPa. Level up is required. Many attempts have been made to improve the mechanical strength. Regarding the impact strength, there is an example in which the strength is improved by a technique for NBR modification of a resin as disclosed in JP-A-3-137151. At present, it is difficult to improve both static strength (bending strength, etc.).
[0003]
[Problems to be solved by the invention]
In the present invention, as a result of various studies to exceed the limit of the mechanical strength of the conventional high strength phenol resin molding material reinforced with glass fiber, D-sorbitol is added to the phenol resin at the time of blending glass fiber and other materials. As a result, the inventors have obtained the knowledge that both the impact strength and the bending strength are improved, and have completed the present invention.
[0004]
[Means for Solving the Problems]
The present invention contains 30-60% by weight of novolac-type phenolic resin, 30-60% by weight of glass fiber, and 1-4% by weight of D-sorbitol as an additive, based on the entire molding material. It relates to a phenolic resin molding material.
[0005]
The novolak type phenolic resin used in the present invention is not particularly limited. However, when a resin having a number average molecular weight of 800 to 1000 and an ortho / para bond ratio with respect to the phenol nucleus of 1 or less is used, at the stage of forming a molding material. Workability, moldability (particularly injection moldability), and the properties of the resulting molded product are relatively good, and it is preferable that hexamethylenetetramine as a curing agent is blended in an amount of 15 to 20% by weight based on the novolac type phenol resin It is preferable to do this.
[0006]
For glass fibers, use of fibers having a fiber diameter of 10 to 15 μm and fiber lengths of 1 to 3 mm is relatively good in workability at the stage of forming a molding material, and the strength of the obtained molded product is relatively good. The amount is preferably 30 to 60% by weight based on the entire molding material. If it is less than 30% by weight, it is difficult to obtain satisfactory strength, and the dimensional change becomes large. In view of the above, it is preferably 30 to 60% by weight.
[0007]
The D-sorbitol used for improving the mechanical strength, which is the object of the present invention, is preferably added in an amount of 1 to 4% by weight based on the entire molding material. This is because if the amount is less than 1% by weight, the effect of improving the strength is low, and if it exceeds 4% by weight, the strength is reduced. Regarding the reason for using D-sorbitol, the melting point is about 90 ° C., it melts at the molding material stage and exerts a plasticizer effect, the viscosity when melted is relatively low, and the dispersibility is good. And so on. Although the action of D-sorbitol is not clear, it has excellent compatibility with the resin, has an inorganic base material such as glass fiber, and a functional group (-OH group) with good wettability, which is like a coupling agent. It is estimated that there is an effect. In particular, it is considered that this effect is increased by having as many as six —OH groups in the monomer.
[0008]
When obtaining the phenol resin molding material of the present invention, after uniformly mixing the above raw materials, knead and pulverize with a kneader such as a roll, a kneader, a twin screw extruder alone or a combination of a roll and another mixer. can get. The phenolic resin molding material of the present invention is excellent in mechanical strength and can be applied to substitutes for metal parts such as automobiles and electric / electronics.
[0009]
【Example】
Hereinafter, the present invention will be described by way of examples. Table 1 shows the composition and characteristics of Examples and Comparative Examples. The test piece for characteristic evaluation was produced by transfer molding, and the evaluation method was performed based on JIS.
[0010]
[Table 1]

As the novolac type phenol resin, one having an ortho / para bond ratio of 0.8 and a number average molecular weight of 900 was used.
[0011]
【The invention's effect】
As is clear from the above examples and comparative examples, the phenolic resin molding material of the present invention is excellent in mechanical strength such as impact strength and static strength, and greatly promotes metal substitution in the automobile and electrical / electronic fields. To do.

Claims (1)

A phenolic resin molding material containing 30 to 60% by weight of a novolac type phenolic resin, 30 to 60% by weight of glass fiber, and 1 to 4% by weight of D-sorbitol as an additive with respect to the whole molding material .