Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-06-28
2002-01-22
Hoke, Veronica P. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S411000, C524S412000
Reexamination Certificate
active
06340721
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to flame-retardant thermoplastic resin compositions and more particularly, relates to flame-retardant thermoplastic resin compositions having excellent mold releasability, heat stability and light resistance.
Flame-retardant ABS resins are widely used in the fields of electrical and electronic appliances, OA equipment and the like because of their capability of providing a good surface appearance to their moldings, excellent moldability and mechanical properties and the like.
In recent years, there has been a tendency that articles of light-color tone are prepared in OA equipment. Since the light-colored articles have a tendency in which the change of color tone in long-time use manifests easily, the resin materials having good light-resistance have come to be used with increasing popularity. Presently, most of these articles are produced by injection molding. With technical innovations in the art of molding, such as automation of the molding operations by the introduction of a hot-runner system and reduction of the molding time, it has been requested for a molding resin material to satisfy the elevated quality requirements and to be free of defective molding. Particularly, as regards the reduction of molding time, it is remarkable that there is a tendency for the so-called whitening phenomenon take place when the molded article is removed, due to reduced cooling time. Therefore, a resin material having good mold releasability is required.
From the environmental and hygienic standpoint, halogenated epoxy oligomers has been used as a flame-retardant which generates little noxious dioxin when burned. Such halogenated epoxy oligomers can be roughly classified into two types: oligomers having epoxy groups at both terminals of the molecular chain (uncapped type) and oligomers in which the terminal epoxy groups have been subjected to ring-opening addition reaction with tribromophenol (capped type).
The uncapped type flame retardants have high light resistance but are very poor in mold releasability and heat stability. On the other hand, the capped type flame retardants exhibit relatively good mold releasability and heat stability but are intolerably low in light resistance. When these two types of flame retardant are used in combination, the deterioration of the respective flame retardants are manifested in the product.
Thus, the mold releasability and light resistance are the antinomic properties, and there is yet available no flame-retardant resin material which is excellent in both mold releasability and light resistance. Therefore, a flame-retardant resin having both excellent releasability and high light resistance has strongly been required.
As a result of the present inventors' earnest studies on the above problem, it has been found that by blending a specific graft copolymer and a specific flame-retardant in a specified ratio, the obtained resin composition shows excellent mold releasability, heat stability and light resistance. The present invention has been attained on the basis of this finding.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a flame-retardant thermoplastic resin composition that has excellent mold releasability, heat stability and light resistance, and is applicable to a wide scope of use.
To attain the object, in a first aspect of the present invention, there is provided a flame-retardant resin composition comprising:
(A) 60 to 98 wt % of a thermoplastic resin comprising a rubber-reinforced resin (A-1) obtained by graft-polymerizing a monomer component (b) comprising an aromatic vinyl compound, or an aromatic vinyl compound and other monomer(s) copolymerizable therewith in the presence of a rubber-like polymer (a), a polymer (A-2) obtained by polymerizing the monomer component (b), or a mixture of the resin (A-1) and the polymer (A-2); and
(B) 40 to 2 wt % of a halogen type flame-retardant which comprises a mixture of compounds represented by the following formula (1), the mixture comprising 5 to 60 mol % of a compound (B-1) having epoxy groups at both terminals of the molecular chain, 15 to 70 mol % of a compound (B-2) having epoxy group at one terminal alone and 5 to 80 mol % of a compound (B-3) having no epoxy group at both terminals:
wherein X is a halogen atom such as bromine or chlorine; n is an integer of 0 or more; i is an integer of 1 to 4; R is a same or different groups of —C(CH
3
)
2
— or —CH
2
—; and R
1
and R
2
are a same or different groups selected from the group consisting of the following formulae (2) and (3):
wherein —Z is a group produced by reacting with a phenolic compound, a carboxylic acid compound, an amine-based compound or an alcoholic compound which are reagents capable of ring-opening addition reaction with the epoxy groups.
In a second aspect of the present invention, there is provided a flame-retardant resin composition comprising:
(A) 60 to 98 wt % of a thermoplastic resin comprising a rubber-reinforced resin (A-1) obtained by graft-polymerizing a monomer component (b) comprising an aromatic vinyl compound or an aromatic vinyl compound and other monomer(s) copolymerizable therewith in the presence of a rubber-like polymer (a), a polymer (A-2) obtained by polymerizing the monomer component (b), or a mixture of the resin (A-1) and the polymer (A-2); and
(B) 40 to 2 wt % of a halogen type flame-retardant which comprises a mixture of compounds represented by the following formula (1), the mixture comprising 5 to 60 mol % of a compound (B-1) having epoxy groups at both terminals of the molecular chain, 15 to 70 mol % of a compound (B-2) having epoxy group at one terminal alone and 5 to 80 mol % of a compound (B-3) having no epoxy group at both terminals:
wherein X is a halogen atom such as bromine or chlorine; n is an integer of 0 or more; i is an integer of 1 to 4; R is a same or different groups of —C(CH
3
)
2
— or —CH
2
—; and R
1
and R
2
are a same or different groups selected from the group consisting of the following formulae (2) and (3):
wherein —Z is a group produced by reacting with a phenolic compound, a carboxylic acid compound, an amine-based compound or an alcoholic compound which are a reagents capable of ring-opening addition reaction with the epoxy groups,
the molar ratio of the total of the alkyl groups derived from the following compound {circle around (1)} and the following compound {circle around (2)} in the compound (B-2) to the trihalogenated phenyl groups derived from the following compound {circle around (3)} in the compound (B-2) being 0.1 to 1:0 to 0.9,
the molar ratio of the total of the alkyl groups derived from the following compound {circle around (1)} and the following compound {circle around (2)} in the compound (B-3) to the trihalogenated phenyl groups derived from the following compound {circle around (3)} in the compound (B-3) being 0.1 to 1:0 to 0.9, and
the mixture of compound in the (B) component being obtained by reacting a halogenated epoxy resin having epoxy groups with at least one compound selected from the group consisting of the following compounds {circle around (1)}, {circle around (2)} and {circle around (3)}.
{circle around (1)} a monocarboxylic acid having C
1
-C
10
alkyl groups
{circle around (2)} a monoalcohol having C
1
-C
10
alkyl groups
{circle around (3)} a trihalogenated phenol
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The component (A) of the composition of the present invention is a thermoplastic resin comprising a rubber-reinforced resin (A-1) and/or a polymer (A-2).
The rubber-reinforced resin (A-1) can be obtained by graft-polymerizing a monomer component (b) comprising an aromatic vinyl compound or an aromatic vinyl compounds and other monomer(s) copolymerizable therewith in the presence of a rubber-like polymer (a). The polymer (A-2) is obtained by polymerizing monomer component (b).
Graft polymerization can be accomplished by conventional methods such as emulsion polymerization, solution polymerization, bu
Hashitani Ryuki
Nagai Hisao
Noro Masahiko
Okada Kouji
Wakao Takeshi
Hoke Veronica P.
Nixon & Vanderhye
Techno Polymer Company Limited
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