JPH03183185A - Liquid crystal polyester printed board - Google Patents

Abstract

PURPOSE:To offer printed boards excellent in solder heat resistance and in molding workability by using a melt-moldable liquid crystal polyester having a specific structural unit. CONSTITUTION:Used is a melt-moldable liquid crystal polyester comprising structural units I, II, III and IV where structural unit I has a 40-90mol% of [I+II+III] and structural units II/III have mol ratios 9/1-1/9. Preferably the structural unit I is a polyester prepared from p-hydroxy benzoic acid; structural unit II is a structural unit consisting of 4,4'-dihydroxybiphenyl; structural unit III is 2,6-dihydroxynaphthalene; and structural unit IV is terephthalic acid. In the case of loading a liquid crystal polyester with filler, preferable loading is 200wt% or less to the liquid crystal polyester 100wt%, particularly, 15-100wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a printed wiring board (hereinafter simply referred to as a printed board) having excellent moldability and heat resistance.

<Prior Art> Printed circuit boards currently in use include thermosetting resins such as phenol resin laminates and epoxy resin laminates, and thermoplastic resins such as polybutylene terephthalate and polyphenylene sulfide.

However, in order to form a desired electrical circuit, the thermosetting resin requires a series of treatments such as resist pattern formation, etching, and resist pattern removal on the copper foil laminate, as well as drilling and punching for attaching circuit components. Alternatively, complicated processes such as external shaping are required, and although machining processes such as drilling and punching can be omitted with thermoplastic resin because it is molded in one piece, there are problems such as insufficient heat resistance during the soldering process. .

In order to solve the above-mentioned problems, recently, Japanese Patent Application Laid-open No. 64-
No. 61087 and Japanese Unexamined Patent Publication No. 64-72586 disclose a method using liquid crystal polyester having excellent mechanical properties, heat resistance, and moldability.

<Problems to be Solved by the Invention> However, the liquid crystal polyesters known from JP-A-64-61086 and JP-A-64-72586 have an insufficient balance between moldability and heat resistance. This makes it difficult to mold thin-walled products, and products with improved moldability have insufficient heat resistance, causing problems such as deformed appearance and blistering of the molded product during the soldering process. It was insufficient as a substrate material.

Therefore, an object of the present invention is to provide a printed circuit board with excellent solder heat resistance and moldability.

Means for Solving the Problems> The present inventors have arrived at the present invention as a result of intensive studies to solve the above problems.

That is, the present invention provides the following structural units (■), O1■, and 0
100 parts by weight of a melt-moldable liquid crystal polyester or the above liquid crystal polyester, consisting of 40 to 90 mol% of m structural units (■ + O 10 ■) and a molar ratio of structural units 0/(lD) of 971 to 1/9 The present invention provides a liquid crystal polyester printed circuit board made of a liquid crystal polyester composition containing 200 parts by weight or less of a filler.

-40-R+ -0-)- .....Kashi+co-R2-co-)- .....Φ One or more groups selected from R2 are one or more groups selected from In the formula, X represents a hydrogen atom or a chlorine atom. ) The above structural unit ■ is p-
It is a structural unit of polyester produced from hydroxybenzoic acid, and the structural unit O is a structural unit consisting of 4,4'-dihydroxybiphenyl, and the structural unit ■ is hydroquinone, 2,6-dihydroxynaphthalene, t-butylhydroquinone, and 3. .3', 5.5"tetramethyl-4,4'
- A structural unit produced from one or more aromatic diols selected from dihydroxybiphenyl and phenylhydroquinone, and the structural unit O is terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,2-bis(phenoxy). One or more aromatic dicarboxylic acids selected from ethane-4,4 dicarboxylic acid, 1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylic acid, and 4,4'-diphenyl ether dicarboxylic acid. The structural units produced are shown in 2.
In 6-hydroxynaphthalene, the structural unit O is most preferably prephthalic acid.

Among the structural units (1) to (2) above, the structural unit (2) accounts for 40 to 90 mol%, preferably 60 to 85 mol% of [10+]. m-building unit ■ is 90 mol% of [■ + O+]
If it is larger, the fluidity of the solution M will decrease and it will solidify during polymerization.
If it is less than 0 mol %, the fluidity will be poor, which is not preferable, and the molar ratio of the structural units 1/2 is from 9/1 to 1/9, preferably from 8/2 to 2/8. 1010~9/
If the ratio is 1.0/10 to 1/9, the sharpness and fluidity will still be poor, making it difficult to achieve the object of the present invention. Further, the structural unit 0 is substantially equimolar to the structural unit [O1°].

The method for producing the liquid crystal polyester used in the present invention is not particularly limited, and it can be produced according to known polyester polycondensation methods.

Furthermore, the melt viscosity of the liquid crystal polyester used in the present invention is 1
0 to 15,000 volts is preferred, particularly 20 to 5.00 volts.
OOO voids are more preferred.

Note that this melt viscosity is a value measured using a Koka-type flow tester at a slip rate of 1,000 (1/sec) at a liquid crystal start temperature +40°C.

On the other hand, the logarithmic viscosity of this liquid crystal polyester is 0.1 g/d
Some can be measured in pentafluorophenol at 11°C and 60°C, in which case values of 0.5 to 20 a/g are preferred, and 1.0 to 15 a/l are particularly preferred.

In addition, when polycondensing the liquid crystal polyester used in the present invention, 4.4
Aromatic dicarboxylic acids such as '-diphenyldicarboxylic acid, 3.3'-diphenyldicarboxylic acid and 2.2'-diphenyldicarboxylic acid; aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and dodecanedioic acid;
cycloaliphatic dicarboxylic acids such as hexahydroterephthalic acid,
Chlorhydroquinone, methylhydroquinone, 4,4
Aromatic diols such as '-dihydroxydiphenyl sulfide, 4.4'-dihydroxybenzophenone, 4.4'-dihydroxydiphenyl ether, 1.4-butanediol, 1,6-hexanediol, neopentyl glycol, 1.4cyclohexanediol , 1.4-
Aliphatic or alicyclic diols such as cyclohexane dimetatool, m-hydroxybenzoic acid, aromatic hydroxycarboxylic acids such as 2.6=hydroxynaphthoic acid, or aromatic imide compounds may be used to the extent that does not impair the purpose of the present invention. Further copolymerization can be carried out in small proportions.

A composition in which a filler is further added to the liquid crystal polyester used in the present invention can be more preferably used in the present invention. When adding a filler, the amount added is preferably 200 parts by weight or less, particularly preferably 15 to 100 parts by weight, based on 100 parts by weight of the liquid crystal polyester.

Fillers that can be used in the present invention include glass fibers, carbon fibers, aromatic polyamide fibers, potassium titanate fibers, gypsum fibers, brass fibers, stainless steel fibers, steel fibers, ceramic fibers, boron whisker fibers, mica, Examples include fibrous, powder, granular, or plate-like inorganic fillers such as talc, silica, calcium carbonate, glass peas, glass flakes, glass microballoons, clay, wollastenite, and titanium oxide.

Among the fillers mentioned above, glass fibers are preferably used. The type of glass fiber is not particularly limited as long as it is generally used for reinforcing resins, and can be selected from, for example, long fiber type, single fiber type chopped strand, milled fiber, etc. Additionally, the glass fibers may be coated or bundled with a thermoplastic resin such as ethylene/vinyl acetate copolymer, a thermosetting resin such as an epoxy resin, or a coupling agent such as a silane type or titanate type, or other It may be treated with a surface treatment agent.

Furthermore, the composition of the present invention may contain antioxidants, heat stabilizers (for example, hindered phenol, hydroquinone, phosphites, and substituted products thereof), ultraviolet absorbers, etc., to the extent that the object of the present invention is not impaired. agents (such as resorcinol, salicylates, benzotriazoles, benzophenones, etc.), lubricants and mold release agents (such as montanic acid and its salts, its esters, its half esters, stearyl alcohol, stearamide and polyethylene waxes), dyes (such as nitrosine) and Customary additives such as colorants, including pigments (e.g. cadmium sulphide, phthalocyanines, carbon black, etc.), plasticizers, Ifv antistatic agents, and other thermoplastics can be added to impart the desired properties. .

It is preferable to melt-knead the resin composition RLCel of the present invention, and a known method can be used for melt-kneading. The composition can be prepared by melt-kneading at a temperature of 380°C.

<Example> The present invention will be further explained below with reference to Examples.

Reference Example 1 994 parts by weight of p-hydroxybenzoic acid, 223 parts by weight of 4,4'-dihydroxybiphenyl, and 147 parts by weight of 2,6-diacedoxynaphthalene were placed in a reaction vessel equipped with a stirrer and a distillation tube.
parts by weight, 299 parts by weight of terephthalic acid and 1 part by weight of acetic anhydride.
077 parts by weight was charged, and acetic acid depolycondensation was carried out under the following conditions.

First, under a nitrogen gas atmosphere at 100 to 250°C for 5 hours,
After reacting at 50 to 330°C for 1.5 hours, 330°C,
The pressure was reduced to 0.5W+HQ in 1 hour, and the reaction was further carried out for 0.5 hours to complete the polycondensation, and a nearly theoretical amount of acetic acid was distilled out, forming a liquid crystal polyester having the following theoretical formula (
a) was obtained.

k/j! / m / n = 80 / 13.
3/6.7/20 In addition, this polyester was placed on the sample stage of a polarizing microscope and the temperature was raised to confirm the optical anisotropy. As a result, the liquid crystal initiation temperature was 296°C, indicating good optical anisotropy. showed that.

Example 1 After mixing 45 parts by weight of glass fiber fi with a ribbon blender to 100 parts by weight of the liquid crystal polyester of Reference Example 1,
The mixture was melted and kneaded at 330° C. using an Oamφ vented extruder to form pellets.

Next, the obtained pellet was subjected to a Sumitomo Nestal injection molding machine Gromat (manufactured by Sumitomo Heavy Industries, Ltd.) under the conditions of a cylinder temperature of 330°C and a mold temperature of 90°C. (1/8″XI/2″X
5″) was molded.

HD T (18,56 kg f /
aa) was measured in accordance with AS'r'MD648, and the state of deformation and blistering after immersion in a solder bath for 10 and 30 seconds was observed, and the highest temperature without deformation and blistering was defined as the solder heat resistance temperature.

The results are shown in Table 1.

Table 1 As is clear from Table 1, the composition made of the liquid crystal polyester of the present invention has a higher solder heat resistance temperature than the commercially available liquid crystal polyester shown in the comparative example, and is suitable for use in printed wiring boards.

<Effects of the Invention> According to the present invention, a printed circuit board with excellent moldability and solder heat resistance can be obtained.

Claims (1)

[Claims] (1) The following structural units (I) (II) (III) and (IV)
The structural unit (I) is [(I) + (II) + (III
)] and the structural units (II)/(III) in a molar ratio of 9/1 to 1/9. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R_1 in the formula is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R_2 is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Numerical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼ Indicates one or more groups selected from. Moreover, X in the formula represents a hydrogen atom or a chlorine atom. ) (2) 20 parts by weight of filler per 100 parts by weight of the liquid crystal polyester according to claim (1).
A liquid crystal polyester printed circuit board comprising a liquid crystal polyester composition containing 0 parts by weight or less.