JP3096142B2 - Liquid crystalline polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystalline polyester resin composition. More specifically, the present invention relates to a liquid crystalline polyester resin composition which is excellent in etching processability after molding, can efficiently apply plating to a molded product, and is excellent in heat resistance and molding processability.

[0002]

2. Description of the Related Art Liquid crystalline polyesters are different from generally known thermoplastic polyesters, such as polybutylene terephthalate and polyethylene terephthalate, and are composed of a rigid polymer. Since it is hard to bend and keeps a rod shape, it has little entanglement of molecules during melting and is oriented in one direction only by receiving a slight shear stress. For such a liquid crystalline polyester, a commonly used injection molding method can be applied, which has advantages of excellent moldability, heat resistance, dimensional stability, etc., but the surface of the molded article is strong. Because of the orientation, the surface layer is easily peeled off and fluff is easily generated, and surface processing such as plating cannot be performed as it is. Therefore, it is conceivable to perform a surface roughening treatment using a chemical such as that used in conventional general resins, but the surface of the liquid crystalline polyester resin molded product is chemically very inert and has affinity. Without an appropriate solvent, the surface cannot be roughened by removing the surface alignment layer. Therefore, it is conceivable to add an inorganic filler or an easily dissolvable additive for weakening the strong orientation of the liquid crystalline polyester resin and roughen the surface with a strong acid or strong alkaline solution. However, in this method,
Depending on the purpose of use, the adhesion strength between the metal film and the material is insufficient. On the other hand, liquid crystalline polyester has a low linear expansion coefficient comparable to that of general metals, and has properties such as heat resistance that does not cause abnormalities even when immersed in a 260 ° C solder bath for 10 seconds.
There has been a demand for a resin composition capable of imparting heat-resistant plating by making use of this property, but a satisfactory resin composition has not yet been known.

[0003]

Means for Solving the Problems The present inventors have made use of the thermally beneficial characteristics of such a liquid crystalline polyester and have produced a surface layer which is easy to peel off without impairing physical and chemical properties. As a result of intensive research on liquid crystalline polyester resin compositions capable of forming a metal film with high adhesion strength on the surface, a liquid crystalline polyester containing an inorganic filler surface-treated with a silane compound having an alkyl group in the molecule The molded article obtained by molding the resin composition is excellent in etching treatment property after molding.After performing the etching treatment, for example, surface treatment with an amphoteric surfactant, and then performing electroplating after electroless plating, The present inventors have found that a metal film having extremely strong adhesion can be formed, and have completed the present invention. That is, the present invention relates to a liquid crystalline polyester resin composition excellent in etching property after molding, which contains an inorganic filler surface-treated with a silane compound having an alkyl group in a molecule.

Conventionally, silane compounds used for surface treatment of resin-filled inorganic materials are generally RSiX ₃ or
It has a structure represented by R ¹ R ² SiHX ₂ and has, in the same molecule, an organic functional group R having a substituent binding to an organic material and a hydrolyzable group X reacting with an inorganic material. On the other hand, the silane-based compound used in the present invention is an alkyl group represented by C _n H _{2n + 1} (n = 1 to 10) in which the organic functional group R ₁ has the above-mentioned structure. The decomposable group X is a chlorine or alkoxy group, and specifically, trialkoxysilane, dialkoxysilane, trichlorosilane and the like having an alkyl group such as methyl and ethyl are suitably used in the present invention. In the present invention, by using a surface-treated inorganic filler with such a specific silane-based compound, an anchor effect appears after the etching treatment of the molded article due to a synergistic effect thereof, and the adhesion of plating is increased. The means for treating the surface of the inorganic filler with the silane compound is not particularly limited. For example, an appropriate amount of the silane compound diluted with a mixed solvent of alcohol and water such as isopropyl alcohol with respect to the surface area of the inorganic filler is used. After kneading with an inorganic filler, the treatment may be performed by heating and drying. The effect of the specific silane compound in the present invention is estimated as follows. That is, unlike the general silane coupling agents vinyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane, methyltriethoxysilane having the above structure is an organic compound capable of bonding to an organic material in its molecular structure. Since there is no functional group, coupling between the organic material and the inorganic material does not occur, and the affinity between the organic material and the inorganic filler changes, so that a surface state in which the adhesion of plating is increased after the etching treatment is obtained. As described above, the specific silane-based compound in the present invention does not cause coupling between an organic material and an inorganic material, and thus has not been conventionally used as a surface treatment agent for an inorganic filler for an organic material. .

[0005] The inorganic filler used in the present invention includes glass beads, glass balloons, glass powder, or periodic table II.
One or two members selected from the group consisting of group elements and their oxides, sulfates, phosphates, silicates, carbonates, or aluminum, silicon, tin, lead, antimony, bismuth elements and their oxides In particular, glass beads or one or more selected from the group consisting of oxides, sulfates, phosphates, and silicates of Group II elements are preferred. Oxides of Group II elements are compounds such as magnesium oxide, calcium oxide, barium oxide, and zinc oxide, and phosphates are magnesium phosphate, calcium phosphate, barium phosphate, zinc phosphate, and the like. Compounds such as magnesium pyrophosphate and calcium pyrophosphate, sulfates are compounds such as magnesium sulfate, calcium sulfate and barium sulfate, and silicates are magnesium silicate, calcium silicate, aluminum silicate, kaolin, talc, clay, It is a compound such as diatomaceous earth and wollastonite, and the carbonate is a compound such as calcium carbonate, magnesium carbonate, barium carbonate and zinc carbonate. Particularly preferred are phosphates. In addition to the above, one or two or more selected from the group consisting of amphoteric metal elements such as aluminum, silicon, tin, lead, antimony, and bismuth, or oxides of the elements are also preferable, and zinc, aluminum, Amphoteric metal elements such as tin and lead and oxides thereof are preferred. The particle size of these finely divided inorganic fillers is 0.01 to
A range of 100 μm, preferably 0.1 to 30 μm, more preferably 0.5 to 10 μm is suitable. If it is less than 0.01 μm, agglomerates are liable to be formed on the surface of the molded article due to poor dispersion, and if it exceeds 100 μm, the smoothness of the molded article deteriorates and a good appearance cannot be obtained.

A fibrous inorganic material is also preferable as the inorganic filler. The fibrous inorganic material is used alone or in combination with the finely divided inorganic filler. As fibrous inorganic substances, glass fiber, milled glass fiber, carbon fiber,
Asbestos fiber, silica fiber, silica / alumina fiber,
Inorganic fibrous substances such as alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, and metal fibrous materials such as stainless steel, aluminum, titanium, copper, and brass. Particularly, glass beads and milled glass fibers are preferable. The shape of these fibrous inorganic substances is 1-30 μm in diameter and 5 μm-1 m in length.
m, particularly preferably in the range of 10 to 100 μm.

The amount of the finely divided inorganic filler is 5 to 80% by weight, preferably 20 to 70% by weight, based on the total amount of the liquid crystalline polyester resin composition. If the amount is less than 5% by weight, an uneven flow mark is generated on the surface of the molded product, and the surface-treated product has uneven etching. On the other hand, if it exceeds 80% by weight, the flowability of the resin is reduced, and a molded article having a good surface cannot be obtained.
At the same time, the mechanical strength of the molded product is undesirably reduced. The amount of the fibrous inorganic substance is 1 to 60% by weight, preferably 5 to 40% by weight, based on the total amount of the liquid crystalline polyester resin composition. However, it is not preferable from the viewpoints of moldability and various physical properties that the total amount of the fine powdery inorganic filler and the fibrous inorganic substance exceeds 85% by weight of the total amount of the composition.

Various methods can be used for blending the inorganic filler surface-treated with colloidal silica into the liquid crystalline polyester, but it is preferable to uniformly knead the mixture by a melt-kneading method using an extruder prior to molding. It is preferable to disperse.

[0009] The etching treatment after the molding is carried out using one or more uniform mixture of at least one selected from acids, alkalis, alcohols and water. The liquid is selected. Examples of the acidic solution include sulfuric acid alone or dichromic acid, chromic anhydride, phosphoric acid, p-toluenesulfonic acid, pyrophosphoric acid,
One or two selected from potassium permanganate aqueous solution and the like
An aqueous solution of a complex system of sulfuric acid and at least one or more species is exemplified. or,
Examples of the alkaline solution include an aqueous solution containing a hydroxide of an alkali metal or a hydroxide of an alkaline earth metal as a main component, and a composite solution obtained by adding an alcohol or other solvent thereto. In etching a liquid crystalline polyester molded article with such a treatment liquid, optimum conditions for immersion in the etchant are appropriately searched and selected according to the composition of the etchant. The general processing conditions are as follows. In the case of an acidic solution, an aqueous solution of 80 to 98% by weight of sulfuric acid is used.
The range is 20 minutes. Preferably, a 90-98% by weight aqueous solution is used at 60-70 ° C for 10-30 minutes. If a particularly preferred example of the treatment conditions is shown, a treatment with a 95% by weight aqueous sulfuric acid solution at 60 ° C. for about 30 minutes is appropriate. In the case of an alkaline solution, an aqueous solution of an alkali metal or alkaline earth metal hydroxide of 20 to 60% by weight is used at 30 to 80 ° C. for 3 to 120 minutes. Preferably, use a 40 to 50% by weight aqueous solution of hydroxide at 40 to 60 ° C.
It takes 10 to 30 minutes. A particularly preferable example of the treatment conditions is a treatment at about 60 ° C. for about 30 minutes with an about 45% by weight solution of potassium hydroxide.

The liquid crystalline polyester in the present invention is:
A melt-processable polyester having the property that the polymer molecular chains take a regular parallel arrangement in the molten state. The state in which molecules are arranged in this manner is often referred to as a liquid crystal state or a nematic phase of a liquid crystal substance. Such polymer molecules are generally elongate, flat, highly rigid along the long axis of the molecule, and have multiple chain-extending bonds, usually in either a coaxial or parallel relationship. Consists of The properties of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizer. More specifically, the anisotropic molten phase can be confirmed by using a Leitz polarizing microscope and observing the molten sample placed on a Leitz hot stage under a nitrogen atmosphere at a magnification of 40 times. The polymer is optically anisotropic. That is,
Transmits light when inspected between crossed polarizers. If the sample is optically anisotropic, polarized light will be transmitted, even in the stationary state. As the constituent components of the polymer forming the anisotropic molten phase as described above, one composed of one or more of aromatic dicarboxylic acid and alicyclic dicarboxylic acid One of aromatic diol, alicyclic diol and aliphatic diol One or more aromatic hydroxy carboxylic acids one or more aromatic thiol carboxylic acids one or more aromatic dithiols, aromatic thiol phenols
One or more than one selected from aromatic hydroxyamines and one or more aromatic diamines, and the polymer forming the anisotropic molten phase is only polyester II) Polythiol ester consisting of polyester III) and polyester IV) consisting of V) Polythiol ester consisting of VI) and polythiol ester consisting of VII) and polyester amide consisting of VIII) and combination of polyester amide and the like This is a polyester which forms an anisotropic molten phase composed of Further, although not included in the category of the combination of the above components, the polymer forming the anisotropic molten phase includes aromatic polyazomethine, and specific examples of such a polymer include poly (nitrilo-2-methyl- 1,4 −
Phenylene nitriloethylidine-1,4-phenyleneethylidine); poly (nitrilo-2-methyl-1,4-phenylene nitrilomethylidine-1,4-phenylene methylidene); and poly (nitrilo-2-chloro-1) , 4-phenylene nitrilomethylidyne-1,4-phenylene methylidyne). Further, although not included in the category of the combination of the above components, polyester carbonate is included as the polymer forming the anisotropic molten phase. It may consist essentially of 4-oxybenzoyl, dioxyphenyl, dioxycarbonyl and terephthaloyl units.

The polyesters of the above-mentioned I), II), III) and the polyesteramides of VIII), which are polymers forming anisotropic molten phases suitable for use in the present invention, form the required repeating units by condensation. It can be produced by various ester forming methods that can react organic monomer compounds having a functional group with each other. For example,
The functional group of these organic monomer compounds is a carboxylic acid group,
It may be a hydroxyl group, an ester group, an acyloxy group, an acid halide, an amine group, or the like. The above-mentioned organic monomer compound can be reacted without a heat exchange fluid by a melt acidosis method. In this method, the monomers are first heated together to form a molten solution of the reactants. As the reaction continues, solid polymer particles become suspended in the liquid. A vacuum may be applied to facilitate removal of by-product volatiles (eg, acetic acid or water) in the final stage of the condensation. Also, a slurry polymerization method can be employed for forming a liquid crystalline polyester suitable for use in the present invention. In this method, the solid product is obtained in suspension in a heat exchange medium. Liquid crystalline polymers suitable for use in the present invention include:
They tend to be substantially insoluble in common solvents and are therefore unsuitable for solution processing. However, as already mentioned, these polymers can be easily processed by conventional melt processing methods. Liquid crystalline polyesters suitable for use in the present invention generally have a weight average molecular weight of about 2,000 to 20.
0,000, preferably about 10,000-50,000, particularly preferably about 20,000-25,000. On the other hand, suitable wholly aromatic polyesteramides generally have a molecular weight of about 5,000 to 50,000, preferably about 10,000 to 30,000, for example 15,000 to 17,000. Such determination of molecular weight can be carried out by gel permeation chromatography and other standard methods without solution formation of polymers, for example by quantifying end groups by infrared spectroscopy on compression molded films. Alternatively, the molecular weight can be measured by using a pentafluorophenol solution and using a light scattering method.

The polymer exhibiting an anisotropic melt phase used in the present invention is preferably an aromatic polyester or an aromatic polyesteramide, and also preferably a polyester partially containing the aromatic polyester and the aromatic polyesteramide in the same molecular chain. It is an example. Preferred examples of the compounds constituting them include naphthalene compounds such as 2,6-naphthalenedicarboxylic acid, 2,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene and 6-hydroxy-2-naphthoic acid, and 4,4′- Biphenyl compounds such as diphenyldicarboxylic acid and 4,4'-dihydroxybiphenyl, compounds represented by the following general formulas (I), (II) or (III):

[0013]

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(Provided that X is a group selected from alkylene (C ₁ -C ₄ ), alkylidene, —O—, —SO—, —SO ₂ —, —S—, and —CO— Y :—( CH ₂ ) _{n - (n = 1 ~4)} , - O (CH 2) n O- group selected from the (n = 1 ~4)) p- hydroxybenzoic acid, terephthalic acid, hydroquinone, p- aminophenol and p- phenylene Para-substituted benzene compounds such as diamines and their nuclei-substituted benzene compounds (substituents are selected from chlorine, bromine, methyl, phenyl and 1-phenylethyl), and meta-substituted benzene compounds such as isophthalic acid and resorcinol is there. The liquid crystalline polyester used in the present invention may be a polyalkylene terephthalate which does not partially show an anisotropic molten phase in the same molecular chain, in addition to the above-mentioned constituent components. In this case, the alkyl group has 2 to 4 carbon atoms. Among the above-mentioned components, those containing one or more compounds selected from a naphthalene compound, a biphenyl compound and a para-substituted benzene compound as essential components are more preferable examples. Among the p-substituted benzene compounds, p-hydroxybenzoic acid, methylhydroquinone and 1-phenylethylhydroquinone are particularly preferred examples. Particularly preferred anisotropic molten phase-forming polyesters for use in the present invention are naphthalene moiety-containing repeating units such as 6-hydroxy-2-naphthoyl, 2,6-dihydroxynaphthalene and 2,6-dicarboxynaphthalene. It is contained in an amount of about 10 mol% or more. Preferred polyesteramides are those containing repeating units of the naphthalene moiety described above and a moiety consisting of 4-aminophenol or 1,4-phenylenediamine. still,
Specific examples of the compounds constituting the components (I) to VIII) and polyesters forming an anisotropic molten phase preferable for use in the present invention are described in JP-A-61-698.
No. 66 is described.

The liquid crystalline polyester resin composition of the present invention can be formed into a molded article by a usual molding method, for example, a molding means such as injection molding, extrusion molding, compression molding, etc., and then degreased if necessary. After the etching process, a normal plating process is performed. That is, after etching, neutralization, wetting, and the like, electroless plating, electroplating, and other treatments are performed to obtain a finished molded product that has been plated.

[0016]

As described above, the liquid crystalline polyester resin composition of the present invention has excellent etching treatment properties after molding, does not cause resin surface layer peeling, has a uniform and dense surface structure, It has strong adhesion to plating, making it possible to expand its use not only to exterior components but also to printed wiring boards.

[0017]

EXAMPLES Hereinafter, the processing method of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Examples 1 to 8 and Comparative Examples 1 to 7 A liquid crystalline polyester resin described below and a filler shown in Tables 1 and 2 (% by weight indicate a value relative to the total amount of the composition) are kneaded and dispersed by a melt kneading method using an extruder. And pelletize,
After drying at 140 ° C. for 3 hours, a 120 × 120 × 3 mm flat plate was formed using a mold temperature-controlled by an injection molding machine. After degreasing the molded flat plate, the surface of the flat plate is etched using an alkaline bath under the conditions shown in the table, washed with water, immersed in a dilute hydrochloric acid solution to neutralize residual alkali components, washed with water, and then washed with an amphoteric surfactant. After immersion and surface treatment, electroless copper plating was performed. Since the peeling strength cannot be measured as it is, electro copper plating is performed immediately after the treatment,
After forming to a thickness of 40 μm, it was cut with a knife so as to form a strip having a width of 10 mm, and the peeling strength was measured by a tensile tester. The peeling speed was 50 mm / min. Example 1
-8, surface treatment with treating agents 1-3 used in Comparative Examples 3-4
Glass beads and milled glass fibers
Due to the surface of glass beads and milled glass fiber
Was treated with treating agents 1 to 3. Specifically,
50% for 20 g of each silane compound corresponding to the agents 1-3
Add isopropyl alcohol aqueous solution to make 1 liter,
Add the solution to 10 kg of each inorganic filler and stir with jacket
After drying at room temperature for 10 minutes, the dryer was adjusted to 105 ° C.
And dried for 4 hours to perform surface treatment, each surface treatment inorganic filling
Materials were prepared and used. The results are shown in Tables 1 and 2. still,
The liquid crystalline polyester used in the examples has the following structural units.

[0018]

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[0019]

[Table 1]

[0020]

[Table 2]

Claims (8)

(57) [Claims] 1. An inorganic filler surface-treated with a silane-based compound having an alkyl group in a molecule.
A liquid crystalline polyester resin composition having excellent etching processability after molding. 2. The liquid crystalline polyester resin composition according to claim 1, wherein the etching treatment is an etching treatment using one or more uniform mixtures of acids, alkalis, alcohols and water. 3. The liquid crystalline polyester resin composition according to claim 1, wherein the silane compound is a trialkoxysilane, dialkoxysilane or trichlorosilane having an alkyl group in the molecule. 4. The inorganic filler is a glass bead, a glass balloon, a glass powder, or an element, an oxide, a sulfate, a phosphate, a silicate, a carbonate, or an aluminum, silicon, or tin group II element of the periodic table. , Lead, antimony, bismuth and its oxides are one or more finely divided inorganic fillers in an amount of 5 to 80% by weight based on the total weight of the composition. The liquid crystalline polyester resin composition according to claim 1, which is: 5. The finely divided inorganic filler has an average particle size of 0.01 to 100.
The liquid crystalline polyester resin composition according to claim 4, which is in the range of µm. 6. The inorganic filler has a diameter of 1 to 30 μm and a length of 5 μm.
2. A fibrous inorganic substance having a particle size in the range of .mu.m to 1 mm, wherein the amount thereof is 1 to 60% by weight based on the total weight of the composition.
The liquid crystalline polyester resin composition according to the above. 7. The inorganic filler is a glass bead, a glass balloon, a glass powder, or a group II element of the periodic table and its oxide, sulfate, phosphate, silicate, carbonate, or aluminum, silicon, tin. , Lead, antimony, bismuth elements and oxides thereof, one or two or more kinds of finely powdered inorganic fillers and fibrous inorganic substances are used in combination, and the total blending amount is a composition The liquid crystalline polyester resin composition according to claim 1, which is present in an amount of 5 to 80% by weight based on the total weight. 8. The liquid crystalline polyester resin composition according to claim 6, wherein the fibrous inorganic substance is glass fiber, milled glass fiber or potassium titanate fiber.