JP2751481B2 - Printed board - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin composition for a printed wiring board having excellent fluidity and heat resistance.

<Prior art> Currently used printed wiring boards include thermosetting resins such as phenolic resin laminates and epoxy resin laminates, and polybutylene terephthalate as a thermoplastic resin.
Polyphenylene sulfite is used.

However, in order to form a desired electric circuit, the thermosetting resin forms a resist pattern on a copper foil laminate, an etching process, a series of processes such as a resist pattern removal, and a hole for mounting a circuit component, Complicated processes such as punching or external processing are required, and machining such as punching and punching in thermoplastic resin can be omitted by integral molding, but there are problems such as insufficient heat resistance in the soldering process. .

In order to solve the above problems, recently, Japanese Patent Laid-Open No.
JP-A-61087 and JP-A-64-72586 disclose a method using a liquid crystal polyester.

<Problems to be solved by the invention> However, Japanese Patent Application Laid-Open Nos.
The liquid crystal polyester known in JP-A-4-72586 or the like has a poor balance between fluidity and heat resistance, so that it is difficult to mold a thin-walled molded product, or a material having improved fluidity has poor heat resistance. Thus, there were problems such as deformation of the appearance in the soldering process and bulging of the molded product.

Accordingly, an object of the present invention is to provide a resin composition for printed wiring boards having excellent solder heat resistance and moldability.

<Means for Solving the Problems> The present inventors have made intensive studies to solve the above problems, and as a result, have reached the present invention.

That is, the present invention provides (1) the following structural units (I), (II), (III) and (I)
V), the sum of the structural units (I) and (II) is 75 to 9 with respect to the total of the structural units (I), (II) and (III).
5 mol%, the structural unit (III) is 25 to 5 mol% with respect to the total of the structural units (I), (II) and (III), and the molar ratio of the structural units (I) and (II) [( I) / (II)] is 75/2
A resin for a printed circuit board containing a melt-moldable liquid crystal polyester that is 5 to 95/5, (However, R ₁ in the formula is R ₂ represents one or more groups selected from And at least one group selected from X in the formula represents a hydrogen atom or a chlorine atom. (2) The resin for a printed circuit board according to the above (1), further comprising 0.2 to 30 parts by weight of an organic flame retardant based on 100 parts by weight of the liquid crystal polyester. Further, the resin for a printed circuit board according to the above (1) or (2), further containing 200 parts by weight or less of a filler, and (4) a print comprising the resin for a printed circuit board according to any one of the above (1) to (4) It is a substrate.

The structural unit (I) is a structural unit formed from p-hydroxybenzoic acid, and the structural unit (II) is 4,4'-dihydroxybiphenyl, hydroquinone, 2,6-dihydroxynaphthalene, t-butylhydroquinone, 3 ′, 5,
A structural unit formed from one or more aromatic diols selected from 5'-tetramethyl-4,4'-dihydroxybiphenyl and phenylhydroquinone is converted into a structural unit (II
I) is a structural unit formed from ethylene glycol, and structural unit (IV) is terephthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bis (phenoxy) ethane-4, Formed from one or more aromatic dicarboxylic acids selected from 4'-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid and 4,4'-diphenyl ether dicarboxylic acid Each of the structural units is shown.

Of these, R ₁ But as R ₂ Is most desirable.

Among the above structural units (I) to (IV), structural unit (I)
And the total of (II) is 75 to 95 mol%, preferably 82 to 93 mol%, more preferably 85 to 90 mol%, based on the total of the structural units (I), (II) and (III). is there. The structural unit (III) is 25 to 5 mol%, preferably 18 to 7 mol%, more preferably 15 to 10 mol%, based on the total of the structural units (I), (II) and (III). is there. 95 mol% of the total of the structural units (I) and (II) is based on the total of the structural units (I), (II) and (III)
If it is larger, the melt fluidity will decrease and solidify during polymerization, and 75
If it is less than mol%, the heat resistance becomes poor, which is not preferable.

Further, the molar ratio of the structural units (I) and (II) [(I) /
(II)] is 75/25 to 95/5, preferably 78/22 to 93/7
It is. If the ratio is less than 75/25 or greater than 95/5, heat resistance and fluidity will be poor, and the object of the present invention cannot be achieved. The structural unit (IV) is substantially equimolar to the sum of the structural units (II) and (III).

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

The melt viscosity of the liquid crystal polyester used in the present invention is
10 to 15,000 poise is preferred, and especially / 20 to 5,000 poise is more preferred.

The melt viscosity is a value measured by a Koka type flow tester under the condition of (liquid crystal onset temperature + 40 ° C.) and a shear rate of 1,000 (1 / second).

On the other hand, the logarithmic viscosity of this liquid crystal polyester can be measured in pentafluorophenol at a concentration of 0.1 g / dl and 60 ° C., preferably 0.5 to 5.0 dl / g, particularly preferably 1.0 to 3.0 dl / g.

In the polycondensation of the liquid crystal polyester used in the present invention, isophthalic acid, 3,3'-diphenyldicarboxylic acid,
Aromatic dicarboxylic acids such as aromatic dicarboxylic acids such as 2,2'-diphenyldicarboxylic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, chlorohydroquinone, methyl Hydroquinone, 4,4'-dihydroxygenyl sulfide, 4,4'-dihydroxybenzophenone, aromatic diols such as 4,4'-dihydroxydiphenyl ether, 1,4-butadiol, 1,6-hexanediol, neopentyl glycol, Aliphatic, alicyclic diols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and m-hydroxybenzoic acid,
An aromatic hydroxycarboxylic acid such as 6-hydroxynaphthoic acid or an aromatic imide compound can be further copolymerized in such a small proportion as not to impair the object of the present invention.

By adding an organic flame retardant to the liquid crystal polyester used in the present invention, it is possible to impart flame retardancy, and when the use of the printed circuit board of the present invention requires flame retardancy for the purpose, It is preferable to add an organic flame retardant and use it as a flame retardant liquid crystal polyester composition.

The organic flame retardant that can be used in the present invention is an organic bromine compound and / or an organic phosphorus compound, and the organic bromine compound has a bromine atom in the molecule, and particularly has a bromine content of 20% by weight or more. preferable. Specifically, low molecular weight organic bromine compounds such as decabromodiphenyl ether and ethylene bis- (tetrabromophthalimide), brominated polycarbonate (for example, a polycarbonate oligomer produced from brominated bisphenol A or a copolymer thereof with bisphenol A) ), Brominated epoxy compounds (for example, a diepoxy compound produced by reacting brominated bisphenol A with epichlorohydrin or a monoepoxy compound obtained by reacting brominated phenols with epichlorohydrin), poly (brominated benzyl acrylate), bromine Polyphenylene ether, brominated bisphenol A, condensate of cyanuric chloride and brominated phenol, brominated polystyrene,
Examples include halogenated polymers and oligomers such as cross-linked brominated polystyrene and cross-linked brominated poly α-methylstyrene, and mixtures thereof. Among them, ethylene bis- (tetrabromophthalimide), brominated epoxy oligomer or polymer, and bromine Brominated polystyrene, cross-linked brominated polystyrene, brominated polyphenylene ether and brominated polycarbonate are preferred, and ethylene bis- (tetrabromophthalimide), brominated polystyrene and brominated polycarbonate are particularly preferred.

The amount of these organic flame retardants added is 100% liquid crystal polyester.
0.2 to 30 parts by weight per part by weight is preferred, more preferably
Although it is 0.5 to 20 parts by weight, since the flame retardancy is closely related to the copolymerization amount of the structural unit (III) of the liquid crystal polyester, the following addition amount is preferable. That is, the amount of the organic bromine compound is preferably 60 to 280 parts by weight, particularly preferably 100 to 200 parts by weight, per 100 parts by weight of the structural unit (III) in the liquid crystal polyester.

The organic phosphorus compound used in the present invention is a compound having a phosphorus atom in the molecule, a compound synthesized from phosphoric acid, phosphorous acid, phosphonic acid, etc., a compound such as phosphine, phosphine oxide, phosphorane or a compound represented by the following structure: Compounds of the formula and polymers containing these compounds as at least one component.

Examples of the polymer include a polymer having the following structural unit.

Among these, the most preferred organic phosphorus compounds are the following polymers.

(In the formula, R ₃ represents hydrogen or a monovalent organic residue, R ₄ represents a divalent organic residue, and Ar represents a trivalent organic residue.) These organic phosphorus compounds are The part may be a metal salt.

The amount of the organic phosphorus compound added is determined by the structural formulas (I) and (I
Liquid crystal polyester 10 comprising I), (III) and (IV)
It is 0.2 to 30 parts by weight, preferably 0.5 to 15 parts by weight, based on 0 part by weight, and is one of the structural units (III) in the liquid crystal polyester.
The amount is preferably 2 to 150 parts by weight, more preferably 10 to 100 parts by weight, based on 00 parts by weight.

In the present invention, the organic phosphorus compound may be an organic phosphorus compound containing bromine, such as a polymer having the following structural unit.

In the liquid crystal polyester of the present invention, the structural unit (III) is 5 to 5 in total with respect to the total of the structural units (I), (III) and (III).
23 mol%, with the above-mentioned flame retardant addition amount, V-0 at 1/32 ″ thickness in the vertical combustion test of UL94 standard (ASTM D790 standard).
Can be When the structural unit (III) is less than 5 mol%, the melting point of the liquid crystal polyester is increased, so that the liquid crystal polyester is decomposed at the time of melting by the flame retardant, and the degree of polymerization is reduced. Undesirably, the molded product drip during combustion. On the other hand, when the structural unit (III) is more than 23 mol%, not only the heat resistance such as the deflection temperature under load is greatly reduced, but also it is necessary to add a large amount of an organic bromine compound or a phosphorus compound to impart flame retardancy. It is necessary to further add a flame retardant auxiliary such as an antimony compound, so that heat resistance and mechanical properties are unpreferably reduced.

In the present invention, a liquid crystal polyester used as a resin for a printed circuit board and a composition further containing a filler with respect to the flame-retardant liquid crystal polyester composition can be more preferably used in the present invention. When a filler is added, the amount is preferably 200 parts by weight or less, more preferably 15 to 100 parts by weight, based on 100 parts by weight of the liquid crystal polyester.

As the filler that can be used in the present invention,
Glass fiber, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, stone fiber, brass fiber, stainless steel fiber, steel fiber, ceramic fiber, boron whisker fiber, mica, talc, silica, calcium carbonate, glass beads, glass flake , Glass micro balloon,
Examples thereof include fibrous, powdery, granular, and plate-like inorganic fillers such as clay, wollastenite, and titanium oxide.

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

Further, the resin for a printed circuit board of the present invention includes an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphites and their substituted products) as long as the object of the present invention is not impaired. UV absorbers (eg, resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants and release agents (eg, montanic acid and its salts, its esters, half esters, stearyl alcohol, stearamide, and polyethylene wax), dyes (eg, nitrosine ) And pigments (for example, cadmium sulfide, phthalocyanine, carbon black, etc.), and other additives such as colorants, plasticizers, antistatic agents, and other thermoplastic resins to impart predetermined properties. it can.

In the case of incorporating other components such as a filler or various additives in the printed board resin of the present invention, it is preferable to melt-knead the liquid crystal polyester and other components,
Known methods can be used for the melt-kneading. For example, the composition can be melt-kneaded at a temperature of 200 to 350 ° C. using a Banbury mixer, a rubber roll machine, a kneader, a single-screw or twin-screw extruder, or the like to obtain a composition.

The printed board of the present invention can be made into a printed board by molding the resin for a disk board as described above, and the molding method is preferably injection molding.

<Example> Hereinafter, the present invention will be described in detail with reference to examples.

Reference Example 1 881 parts by weight of p-hydroxybenzoic acid, 158 parts by weight of 4,4'-dihydroxybiphenyl, 907 parts by weight of acetic anhydride, 141 parts by weight of terephthalic acid and 245 parts by weight of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g The reaction vessel was equipped with a stirring blade and a distilling tube, and was subjected to deacetic acid polycondensation under the following conditions.

First, under nitrogen atmosphere, 100 ~ 250 ℃ for 5 hours, 250 ~ 3
After reacting at 00 ° C for 1.5 hours, 0.5mmH at 300 ° C for 1 hour
g, and the mixture was further reacted for 2.25 hours to complete the polycondensation. As a result, a stoichiometric amount of acetic acid was distilled off, and a resin (a) having the following theoretical structural formula was obtained.

k / l / m / n = 75/10/15/25 Moreover, as a result of placing this polyester on a sample stage of a polarizing microscope and raising the temperature to confirm the optical anisotropy, the liquid crystal onset temperature was 264 ° C. And showed good optical anisotropy. The logarithmic viscosity of this polyester (measured at 60 ° C. in pentafluorophenol at a concentration of 0.1 g / dl) is 1.96 dl / g,
The melt viscosity at 304 ° C. and a shear rate of 1000 (1 / second) was 910 poise.

Example 1 8.5 parts by weight of brominated polystyrene ("Pyrocheck" 68PB manufactured by Nissan Fellow Co., Ltd.) and 50 parts by weight of glass fiber were mixed with 100 parts by weight of the liquid crystal polyester (a) of Reference Example 1 using a ribbon blender. The mixture was melt-kneaded and pelletized at 300 ° C. using a 40 mmφ vented extruder.

Next, the obtained pellets were supplied to a Sumitomo Nestal injection molding machine Promat (manufactured by Sumitomo Heavy Industries, Ltd.), and the combustion test pieces (1/3
2 "and 1/8" x 1/2 "x 5"), deflection temperature under load (HD
T) and a test piece for measuring solder heat resistance (1/8 "x 1/2" x
5 ").

These specimens were subjected to a vertical burning test according to UL94 standard, and an HDT (18.56 kgf / cm ² ) was measured according to ASTM D648. The maximum temperature at which no deformation or swelling was observed after immersion in a solder bath for 10 seconds or 30 seconds and deformation was observed was defined as the solder heat resistant temperature. The results are shown in Table 1.

As is clear from Table 1, the composition comprising the liquid crystal polyester of the present invention has a higher solder heat resistance than the commercially available liquid crystal polyester shown in Comparative Examples, and is suitable for printed circuit boards.

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

Claims (4)

(57) [Claims] (1) It comprises the following structural units (I), (II), (III) and (IV), and the total of the structural units (I) and (II) is the same as the structural units (I), (II) and (III) ), And the structural unit (III) is 25-5 mol% with respect to the total of the structural units (I), (II) and (III), and the structural unit (I) The molar ratio of (II) [(I)
/ (II)] is a resin for printed circuit boards containing a melt-moldable liquid crystal polyester having a ratio of 75/25 to 95/5. (However, R ₁ in the formula is R ₂ represents one or more groups selected from And at least one group selected from X in the formula represents a hydrogen atom or a chlorine atom. ) 2. The resin for a printed board according to claim 1, further comprising 0.2 to 30 parts by weight of an organic flame retardant based on 100 parts by weight of the liquid crystal polyester. 3. The composition according to claim 1, further comprising a filler of 200 parts by weight or less based on 100 parts by weight of the liquid crystal polyester.
Or the resin for printed circuit boards according to (2). 4. A printed circuit board made of the resin for a printed circuit board according to any one of claims (1) to (3).