Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-05-10
2002-02-12
Hoke, Veronica P. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C523S217000
Reexamination Certificate
active
06346568
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid crystal polyester resin composition. More specifically, the present invention relates to a liquid crystal polyester resin composition which is prepared by compounding glass fiber which has been surface-treated with a thermosetting resin.
2. Description of the Related Art
A liquid crystal polyester resin (hereinafter, referred to as liquid crystal polyester) which manifests liquid crystal property in melting is excellent in heat-resistance, and is excellent in flowability, namely processability in melting, therefore, the liquid crystal polyester is used, as a molding material which can provide precise molding, in various fields typically including electric and electronic fields. Particularly, a resin composition obtained by filling a fibrous reinforcing material such as glass fiber or the like which has been surface-treated with a thermosetting resin, into a liquid crystal polyester resin is a material suitable for electric and electronic parts having thin parts or complicated forms.
However, since this resin composition has a high processing temperature, there may sometimes occur deterioration and decomposition of the resin composition due to heat, further, generation of a decomposed gas, for example, in a melt-extrusion for obtaining a resin composition in the form of pellets to be subjected to injection molding, or in a injection-molding process of a resin composition. Since a part of deteriorated materials such as gasses and the like in processing is embedded in a molded article, when the molded article is used as parts, various problems, for example, blister due to generation of a gas in a solder process, may occur.
SUMMARY OF THE INVENTION
The object of the present invention is to solve the above-described problems and provide a glass fiber-compounded liquid crystal polyester resin composition having excellent mechanical-property and heat-resistance, particularly, solder heat-resistance.
That is, the present invention is a liquid crystal polyester resin composition comprising a liquid crystal polyester resin and surface-treated glass fiber with a thermosetting resin, wherein the ignition loss of the surface-treated glass fiber is from 0.05 to 0.4% by weight, and a molded article obtained by using the same.
The liquid crystal polyester resin composition of the present invention can be prepared by compounding glass fiber which has been surface-treated with a thermosetting resin, and has the ignition loss of from 0.05 to 0.4% by weight, into a liquid crystal polyester resin.
DETAILED DESCRIPTION OF THE INVENTION
As the liquid crystal polyester resin to be used in the present invention, exemplified are:
(1) Polyesters composed of a combination of an aromatic dicarboxylic acid, aromatic diol and aromatic hydroxycarboxylic acid,
(2) Polyesters composed of different aromatic hydroxycarboxylic acid,
(3) Polyesters composed of a combination of an aromatic dicarboxylic acid and aromatic diol,
(4) Polyesters obtained by reacting a polyester such as polyethylene terephthalate and the like with an aromatic hydroxycarboxylic acid, and the like,
and preferables are those forming isotropic melt at a temperature of not more than 400° C. from the standpoint of molding processing. Further, instead of the above-described aromatic dicarboxylic acid, aromatic diol and aromatic hydroxycarboxylic acid, ester-forming derivatives thereof may also be used.
As the repeating structure unit of the liquid crystal polyester include, the following structure units may be exemplified.
Repeating structure units derived from aromatic hydroxycarboxylic acids:
Repeating structure units derived from aromatic dicarboxylic acids:
Repeating structure units derived from aromatic diols:
In the definition of the above substituents X1 to X3, “H”is a hydrogen atom, “alkyl ” is preferably an alkyl group having 1 to 10 carbon atoms, and “aryl” is preferably an aryl group having 6 to 20 carbon atoms.
The liquid crystal polyester which is particularly preferable from the standpoint of balance between heat-resistance, mechanical property and processability is a liquid crystal polyester resin containing a repeating structure unit represented by (A
1
) in an amount of at least 30 mol %. Specifically, those having repeating structure units as shown in the following (a) to (f) are preferable.
(a): combination of (A
1
), (B
1
) or a mixture of (B
1
) and (B
2
), (C
1
)
(b): combination of (A
1
), (A
2
)
(c): combination (a) wherein a part of (A
1
) is substituted by (A
2
)
(d): combination (a) wherein a part of (B
1
) is substituted by (B
3
)
(e): combination (a) wherein a part of (C
1
) is substituted by (C
3
)
(f): combination (b) wherein the structure units of (B
1
) and (C
2
) are added
Known methods can be adopted for preparing liquid crystal polyester resins used in the present invention. For example, liquid crystal polyester resins of (a) and (b) are described in Japanese Patent Kokoku Publication (JP-B) Nos. 47-47870, 63-3888, and the like.
The glass fiber used for the present invention is generally fiber which is obtained by processing glass mainly composed of a silicate salt into fibrous form. Examples of the glass include alkaline glass for general purpose (A glass), acid-resistant glass for chemical use (C glass), low density glass (D glass), borosilicate glass (E glass) and the like, and E glass is preferable from the stand point of the strength of a molded article obtained by using the resulted resin composition, and the like. For producing glass fiber, there is generally used a method in which glass in melted state (1300° C. or more) is spun. The glass fiber may also be treated with a silane-based coupling agent, titanium-based coupling agent or the like, if necessary.
The surface treatment of glass fiber with a thermosetting resin means coating treatment of a part or all of the surface of glass fiber with an un-cured or cured thermosetting resin, as well as sizing treatment of glass fiber. This surface treatment contributes to handling property of glass fiber, affinity with a liquid crystal polyester resin, and the like.
For the surface treatment of glass fiber with a thermosetting resin, there is usually a procedure in which a thermosetting resin is made into an emulsion with an anionic, cationic or nonionic surfactant, glass fiber which has been melt-spun is immersed into the emulsion, and moisture is removed by drying. If necessary, the thermosetting resin may sometimes be cured by heating. Further, it is also useful to previously introduced the above-described coupling agent into the thermosetting resin.
As the thermosetting resin, epoxy resins, urethane resins and epoxyurethane resins are preferable from the standpoints of heat-resistance, handling property and the like, and particularly, urethane resins, or epoxyurethane resins are preferable. Further, combinations of two or more thermosetting resins, such as a combination of an epoxy resin and an urethane resin, may also be adopted. As the un-cured urethane resin, an isocyanate can be used singly or a mixed solution of an isocyanate and a polyol can be used. If necessary, a catalyst such as an amine and the like may also be contained. Further, a part of the un-cured urethane resin may also be cured. Examples of the isocyanate include tolylene dlisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI) and the like, and examples of the polyol include various polyether polyols, polyester polyols and the like. The epoxyurethane resin used in the present invention includes: a resin obtained by combining an epoxy resin having a hydroxy group with an isocyanate compound; and a resin obtained by ring-opening a part of epoxy groups in an epoxy resin using an amine or alcohol to obtain an epoxy resin having a hydroxyl group, then, combining this with an isocyanate compound, without being limited thereto.
In the present invention, the ignition loss of the glass fiber which has been surface-treated with a thermosetting resin is from 0.05 to 0
Maeda Mituo
Nakamura Hiroshi
Birch & Stewart Kolasch & Birch, LLP
Hoke Veronica P.
Sumitomo Chemical Company Limited
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