Stock material or miscellaneous articles – Pile or nap type surface or component – Flock surface
Reexamination Certificate
1999-11-26
2004-01-27
Jackson, Monique R. (Department: 1773)
Stock material or miscellaneous articles
Pile or nap type surface or component
Flock surface
C428S213000, C428S323000, C428S328000, C428S330000, C428S500000, C428S515000, C428S516000, C428S920000, C428S921000
Reexamination Certificate
active
06682801
ABSTRACT:
FILED OF THE INVENTION
The present invention relates to a molded article of a synthetic resin filled with a halogen-free flame retardant. More specifically, it relates to a high-strength and highly flame-retardant molded article comprising a base material formed of a composition containing a synthetic resin, a metal hydroxide, red phosphorus and a carbon powder and colored in a color range of from dark red to black and a skin layer laminated thereon. In the above molded article, the surface color of the base material is masked with the skin layer, the color tone of the molded article can be modified to a color as required, and a decrease in electric insulation resistance of the molded article is small when the molded article is submerged.
PRIOR ART OF THE INVENTION
In the fields of molded articles formed of a resin composition containing a halogen-free flame retardant, it is old-established practice to use metal hydroxide as a flame retardant. Since metal hydroxides such as magnesium hydroxide and aluminum hydroxide are white, a molded article can be colored with a colorant as required, and the demand of these metal hydroxides is expected to expand in the future since they are safe flame retardants. However, the defect of the above metal hydroxides is that they have a small effect on imparting flame retardancy, and for imparting a synthetic resin with sufficient flame retardancy, it is required to fill a high density of the above flame retardant, or it is required to incorporate approximately 100 parts by weight of the flame retardant or more per 100 parts by weight of the synthetic resin. The use of such a high density of the metal hydroxide in a synthetic resin considerably downgrades the inherent mechanical strength and surface appearance of the synthetic resin in many cases. Actually, therefore, fields where the above metal hydroxides are usable as a flame retardant for a synthetic resin are limited.
For overcoming the above problem, there has been long proposed a method in which a synthetic resin is improved in flame retardancy by incorporating red phosphorus or a carbon powder as a flame retardant aid in combination with the metal hydroxide. According to this method, halogen-free flame redardants alone are used, and there can be produced a molded article of a synthetic resin having high strength and high flame retardancy equivalent to those of a molded article of a PVC resin or a resin filled with a halogen-containing flame retardant. When red phosphorus or a carbon powder is used, however, a molded article is colored in dark red or black, and there are caused problems that the use of the molded article is limited in applicable field and that the molded article extremely decreases in electric insulation resistance when submerged. For overcoming the coloring problem of the red phosphorus, JP-B-7-30326 and JP-A-6-128413 propose a method in which the red phosphorus is surface-coated with an inorganic pigment such as titanium oxide or zinc sulfate for masking the dark red color of the red phosphorus. That is, a whitened red phosphorus is proposed.
In the above method, red phosphorus can be whitened to some extent. However, the whitening is not sufficient, and a molded article formed of a resin composition containing the above whitened red phosphorus has a pinkish white color, so that the color of a molded article cannot be modified to an intended sufficiently white. It is therefore very difficult to completely color the molded article in an intended color by adding a colorant. Further, for whitening red phosphorus, it is required to incorporate a large amount of colorants such as titanium oxide and zinc sulfate. The actual problem is therefore that the content of red phosphorus decreases, so that the effect that the red phosphorus imparts a synthetic resin with flame retardancy decreases to a great extent.
SUMMARY OF THE INVENTION
Under the above circumstances of prior art methods, it is an object of the present invention to completely overcome the coloring problem of a molded article surface in the prior art methods while retaining the advantages of high strength and high flame retardancy of a molded article when a metal hydroxide is used in combination with red phosphorus and a carbon powder in the method of imparting a synthetic resin with flame retardancy.
It is another object of the present invention to decrease the lowering of the electric insulation resistance of a molded article when the molded article is submerged.
According to the present invention, there is provided a molded article which is colored in any color, which has high strength and high flame retardancy and which exhibits the decreased lowering of electric insulation resistance when submerged, the molded article comprising a base material A colored in a color of from dark red to black and a skin layer B laminated thereon, the skin layer B masking a colored surface of the base material A,
wherein the base material A is a molded product formed of a composition containing 100 parts by weight of a synthetic resin, 5 to 200 parts by weight of a metal hydroxide, 1 to 30 parts by weight of red phosphorus and 0.1 to 30 parts by weight of a carbon powder, and
the skin layer B is a molded product formed of a composition containing 100 parts by weight of a synthetic resin, 0 to 100 parts by weight of a pigment and 0 to 200 parts by weight of a metal hydroxide, provided that the total amount of the pigment and the metal hydroxide in the skin layer B is at least 0.001 part by weight.
DETAILED DESCRIPTION OF THE INVENTION
The molded article of the present invention is constituted of the above base material A and the above skin layer B. The base material A is basically a molded article having high strength and high flame retardancy. However, it has a surface colored in a color of from dark red to black, and it shows a great decrease in electric insulation resistance when submerged. The skin layer B is used for masking the surface color of the base material A and preventing a decrease in electric insulation resistance when the molded article is submerged. Further, when the entire surface of the base material A is covered with the skin layer B, the phosphine odor inherent to a molded article containing red phosphorus can be completely prevented. In the present invention, the method of laminating or stacking the base material A and the skin layer B is not specially limited. The skin layer B may be laminated on the base material A by any method so long as the skin layer B covers the entire surface of the base material A. The present invention can use, for example, a method in which the base material A treated by corona discharge and the skin layer B are bonded to each other with an adhesive, a method in which the base material A and the skin layer B are laminated by co-extrusion, a method in which the base material A is skin-packed with the skin layer B, a method in which the base material A and the skin layer B which are injection-molded plates are compression-molded, a method in which the base material A and the skin layer B are laminated with a resin molded product of an adhesive resin, etc., being present between the base material A and the skin layer B, a method in which the base material A and/or the skin layer B are/is printed beforehand and these are laminated, or a method in which a stretched film (skin layer B) is laminated on the base material A. Any laminating method may be used regardless of whether the method is a direct method or an indirect method, so long as the skin layer B forms a surface of a molded article. Further, the form of the molded article is not limited. There are many cases where it is difficult to laminate the base material A and the skin layer B due to their poor adhesion. In such cases, preferably, the base material A and the skin layer B are discharge-treated for easier lamination. The discharge method includes a corona discharge method and a glow discharge method. The discharge treatment is not necessarily required when the base material A and the skin layer B are easily bonded to each ot
Imahashi Takeshi
Sawa Yoshiharu
Yoshii Makoto
Jackson Monique R.
Kyowa Chemical Industry Co. Ltd.
Wenderoth Lind & Ponack LLP
LandOfFree
Flame-retardant laminated resin molded article does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flame-retardant laminated resin molded article, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flame-retardant laminated resin molded article will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3190656