JP6829035B2 - Liquid crystal resin composition and high fluidizing agent for liquid crystal resin - Google Patents

Description

The present invention relates to a liquid crystal resin composition and a high fluidizing agent for a liquid crystal resin.

The liquid crystal resin is a resin having high fluidity during molding among various thermoplastic resins. In recent years, with the miniaturization and complicated shape of molded products, liquid crystal resins are required to have improved fluidity at the time of melting. Examples of the method for obtaining high fluidity at the time of melting include a method of changing the chemical species of the molecular skeleton of the liquid crystal resin and a method of changing the type and amount of the filler. However, if the chemical species of the molecular skeleton is changed, it is necessary to newly perform various evaluations on the liquid crystal resin from the beginning, and the load on the process in the production of the liquid crystal resin increases. In addition to these, it is difficult to maintain the physical characteristics of the existing liquid crystal resin. Specifically, even if the fluidity at the time of melting is improved, it is evaluated by other characteristics, particularly heat resistance evaluated by the deflection temperature under load (hereinafter, also referred to as "DTUL"), molding temperature and the like. There is a high possibility of losing workability.

Therefore, a technique has been reported in which a high fluidity agent such as an aromatic amine compound is kneaded and added to an existing liquid crystal resin to improve the fluidity of the liquid crystal resin at the time of melting. For example, Patent Document 1 describes a liquid crystal resin composition using 4-aminophenol as a high fluidizing agent.

Special Table 2002-511513 Gazette

However, according to the studies by the present inventors, conventional high fluidity agents such as aromatic amine compounds can sufficiently improve the fluidity of the liquid crystal resin at the time of melting unless it is used in an amount of several mass%. It turned out that it couldn't be done.

The present invention has been made to solve the above problems, and an object thereof is a liquid crystal having excellent fluidity at the time of melting even if the content of a high fluidizing agent is small while maintaining heat resistance. An object of the present invention is to provide a sex resin composition and a high fluidizing agent for a liquid crystal resin.

The present inventors have conducted intensive studies to solve the above problems. As a result, they have found that the above problems can be solved by using an aliphatic nitrogen-containing compound having an electron-withdrawing group as a high fluidizing agent for a liquid crystal resin, and have completed the present invention. More specifically, the present invention provides the following.

(1) A liquid crystal resin composition containing (A) a liquid crystal resin and (B) an aliphatic nitrogen-containing compound having an electron-withdrawing group.

(2) The composition according to (1), wherein the component (B) is an aliphatic amine compound having an electron-withdrawing group.

(3) The composition according to claim (1) or (2), wherein the electron-withdrawing group is at least one selected from the group consisting of a carboxyl group and a cyano group.

(4) The composition according to any one of (1) to (3), wherein the content of the component (B) is 0.02% by mass or more and 1.3% by mass or less in the composition. Composition.

(5) (B) A high fluidizing agent for liquid crystal resins made of an aliphatic nitrogen-containing compound having an electron-withdrawing group.

According to the present invention, a liquid crystal resin composition having excellent fluidity at the time of melting and a high fluidizing agent for liquid crystal resin while maintaining heat resistance even if the content of the high fluidizing agent is small. Can be provided.

Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following embodiments.

<Liquid crystal resin composition>
The liquid crystal resin composition according to the present invention contains (A) a liquid crystal resin and (B) an aliphatic nitrogen-containing compound having an electron-withdrawing group.

[(A) Liquid crystal resin]
The liquid crystal resin (A) used in the present invention refers to a melt-processable polymer having a property of forming an optically anisotropic molten phase. The properties of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizing element. More specifically, the confirmation of the anisotropic molten phase can be carried out by observing the molten sample placed on the Leitz hot stage at a magnification of 40 times under a nitrogen atmosphere using a Leitz polarizing microscope. Liquid crystalline polymers applicable to the present invention normally transmit polarized light and are optically anisotropy when inspected between orthogonal polarizers, even in the molten and resting state.

The type of the liquid crystal resin (A) as described above is not particularly limited, and is preferably an aromatic polyester and / or an aromatic polyester amide. The range also includes polyesters that partially contain aromatic polyesters and / or aromatic polyester amides in the same molecular chain. The liquid crystal resin (A) preferably at least about 2.0 dl / g, more preferably 2.0 to 10.0 dl / g when dissolved in pentafluorophenol at 60 ° C. at a concentration of 0.1% by mass. Those having a logarithmic viscosity (IV) of are preferably used.

The aromatic polyester or aromatic polyesteramide as the (A) liquid crystal resin applicable to the present invention is particularly preferably at least one selected from the group consisting of aromatic hydroxycarboxylic acid, aromatic hydroxyamine, and aromatic diamine. It is an aromatic polyester or an aromatic polyester amide having a constituent unit derived from a species compound as a constituent.

More specifically
(1) Polyester mainly composed of a constituent unit derived from one or more kinds of aromatic hydroxycarboxylic acid and its derivative;
(2) A structural unit derived mainly from (a) one or more kinds of aromatic hydroxycarboxylic acids and derivatives thereof, and (b) one kind of aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof. Or a polyester composed of a constituent unit derived from two or more kinds and (c) a constituent unit derived from at least one kind or two or more kinds of aromatic diols, alicyclic diols, aliphatic diols, and derivatives thereof;
(3) Constituent units derived mainly from (a) one or more of aromatic hydroxycarboxylic acids and derivatives thereof, and (b) one or two of aromatic hydroxyamines, aromatic diamines, and their derivatives. Polyesteramides consisting of structural units derived from species or higher and (c) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and structural units derived from one or more of their derivatives;
(4) Constituent units derived mainly from (a) one or more of aromatic hydroxycarboxylic acids and derivatives thereof, and (b) one or two of aromatic hydroxyamines, aromatic diamines, and derivatives thereof. Constituent units derived from species or more, (c) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and structural units derived from one or more of their derivatives, and (d) aromatic diols, alicyclics. Examples thereof include a polyester amide composed of a group diol, an aliphatic diol, and a structural unit derived from at least one or more of the derivatives thereof. Further, a molecular weight adjusting agent may be used in combination with the above-mentioned constituent components, if necessary.

（Ｘ：アルキレン（Ｃ_１〜Ｃ_４）、アルキリデン、−Ｏ−、−ＳＯ−、−ＳＯ_２−、−Ｓ−、及び−ＣＯ−より選ばれる基である）

（Ｙ：−（ＣＨ_２）_ｎ−（ｎ＝１〜４）及び−Ｏ（ＣＨ_２）_ｎＯ−（ｎ＝１〜４）より選ばれる基である。） Preferred examples of the specific compound constituting the (A) liquid crystal resin applicable to the present invention include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, and 2,6-dihydroxy. Aromatic diols such as naphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcin, a compound represented by the following general formula (I), and a compound represented by the following general formula (II). Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and compounds represented by the following general formula (III); p-aminophenol, p- Examples thereof include aromatic amines such as phenylenediamine and 4-acetoxyaminophenol.

(X: A group selected from alkylene (C _{1 to} C ₄ ), alkylidene, -O-, -SO-, -SO _2- , -S-, and -CO-)

(Y: A group selected from − (CH ₂ ) _n − (n = 1-4) and −O (CH ₂ ) _n O − (n = 1-4).)

The liquid crystal resin (A) used in the present invention can be prepared from the above-mentioned monomer compound (or mixture of monomers) by a known method using a direct polymerization method or a transesterification method, and is usually a melt polymerization method. Or slurry polymerization method or the like is used. The above compounds having an ester-forming ability may be used in the polymerization as they are, or may be modified from a precursor to a derivative having the ester-forming ability in the pre-polymerization step. Various catalysts can be used for these polymerizations, and typical ones are dialkyltin oxide, diaryltin oxide, titanium dioxide, alkoxytitanium silicates, titanium alcoholates, and alkalis of carboxylic acids. And alkaline earth metal salts, Lewis acid salts such as BF _{3 and} the like. The amount of the catalyst used is generally preferably about 0.001 to 1% by mass, particularly preferably about 0.01 to 0.2% by mass, based on the total mass of the monomer. If necessary, the polymer produced by these polymerization methods can be increased in molecular weight by solid-phase polymerization under reduced pressure or heated in an inert gas.

The melt viscosity of the liquid crystal resin (A) obtained by the above method is not particularly limited. Generally, a melt viscosity at a molding temperature of 10 MPa or more and 600 MPa or less at a shear rate of 1000 sec ^-1 can be used. However, the one having a very high viscosity by itself is not preferable because the fluidity is very deteriorated. The liquid crystal resin (A) may be a mixture of two or more kinds of liquid crystal resins.

The content of the component (A) is preferably 98.7% by mass or more and 99.98% by mass or less, more preferably 99.0% by mass or more and 99.97% by mass or less in the liquid crystal resin composition according to the present invention. , Even more preferably 99.5% by mass or more and 99.96% by mass or less. When the liquid crystal resin composition according to the present invention contains other components, particularly a filler, the content of the component (A) is preferably 55% by mass or more of 85 in the liquid crystal resin composition according to the present invention. It is mass% or less, more preferably 60% by mass or more and 80% by mass or less, and even more preferably 65% by mass or more and 75% by mass or less. When the content of the component (A) is within the above range, the liquid crystal resin composition according to the present invention tends to improve the fluidity at the time of melting while maintaining the heat resistance.

[(B) Aliphatic nitrogen-containing compound having an electron-withdrawing group]
The component (B) is an aliphatic nitrogen-containing compound having an electron-withdrawing group, and functions as a high fluidizing agent for a liquid crystal resin. The liquid crystal resin composition according to the present invention is excellent in fluidity at the time of melting while maintaining heat resistance even if the content of the component (B) is small. The component (B) may be used alone or in combination of two or more.

Examples of the component (B) include an aliphatic amine compound having an electron-withdrawing group, an aliphatic quaternary ammonium compound with an electron-withdrawing group, and the like, availability, handleability, and a liquid liquid resin composition obtained. From the viewpoint of fluidity at the time of melting the substance, an aliphatic amine compound having an electron-withdrawing group is preferable. The aliphatic amine compound having an electron-withdrawing group is not particularly limited, and amino acids, oligopeptides which are quantities of amino acids, dicyandiamide and the like are preferably exemplified in that they are harmless to the human body, the environment and the like. .. The amino acid is not particularly limited, and examples thereof include arginine, glycine, and asparagine. The oligopeptides, not particularly limited, for example, dipeptides, tripeptides, tetrapeptides, pentapeptides, hexapeptides and the like, more specifically, for example, glycylglycine, N ^alpha - glycyl -L- aspartic , L-alanyl-L-glutamine and other dipeptides.

The electron-withdrawing group in the component (B) is not particularly limited, and examples thereof include a carboxyl group, a cyano group, an aldehyde group, a nitro group, and a combination of two or more of these, and safety can be obtained. From the viewpoint of fluidity at the time of melting of the liquid crystal resin composition, at least one selected from the group consisting of a carboxyl group and a cyano group is preferable. The number of electron-withdrawing groups in the component (B) is not particularly limited, and examples thereof include one or more, preferably one or two from the viewpoint of availability, handleability, and the like, and one is more preferable. preferable.

When the component (B) is the above aliphatic amine compound, the amino group in the component (B) may be any of a primary amino group, a secondary amino group, and a tertiary amino group, and these 2 It may be a combination of seeds or more. In the same case, the number of amino groups in the component (B) is not particularly limited, and examples thereof include one or more, preferably 1 to 4 from the viewpoint of availability, handleability, and the like. Three are more preferred.

The number of carbon atoms of the component (B) is not particularly limited, and examples thereof include 1 to 8 carbon atoms. From the viewpoint of availability, handleability, etc., 2 to 6 carbon atoms are preferable, and 2 to 4 carbon atoms are more preferable. 2-3 are even more preferred, and 2 are particularly preferred.

The molecular weight of the component (B) is not particularly limited, and examples thereof include 250 or less. From the viewpoint of availability, handleability, etc., 40 to 200 is preferable, 50 to 180 is more preferable, and 70 to 90 is further added. More preferred.

The content of the component (B) is preferably 0.02% by mass or more and 1.3% by mass or less, more preferably 0.03% by mass or more and 1.0% by mass or less in the liquid crystal resin composition according to the present invention. , Even more preferably 0.04% by mass or more and 0.5% by mass or less. When the content of the component (B) is within the above range, the fluidity of the liquid crystal resin composition according to the present invention at the time of melting is effective while suppressing the amount of the component (B) which is a high fluidizing agent. Can be improved.

[Other ingredients]
The liquid crystal resin composition according to the present invention includes other polymers, fillers, and known substances generally added to synthetic resins, that is, antioxidants and ultraviolet absorbers, as long as the effects of the present invention are not impaired. Stabilizers such as stabilizers, antistatic agents, flame retardants, colorants such as dyes and pigments, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents, lubricants and the like can also be appropriately added depending on the required performance.

Examples of other polymers include epoxy group-containing copolymers. Examples of the filler include a fibrous filler such as glass fiber; a granular filler such as silica; a plate-like filler such as mica; and carbon black.

The content of other components, particularly the filler, is preferably 13.7% by mass or more and 44.98% by mass or less, more preferably 19% by mass or more and 39.97% by mass in the liquid crystal resin composition according to the present invention. % Or less, and even more preferably 24.5% by mass or more and 34.96% by mass or less. When the content of other components, particularly the filler, is within the above range, the liquid crystal resin composition according to the present invention tends to improve the fluidity at the time of melting while maintaining the heat resistance.

[Preparation of liquid crystal resin composition]
The preparation of the liquid crystal resin composition according to the present invention is not particularly limited. For example, the liquid crystal resin composition can be prepared by blending the component (A), the component (B), and optionally other components, and melt-kneading them using a single-screw or twin-screw extruder. Will be done.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

<Liquid crystal resin>
-Liquid crystal polyester resin (LCP1)
After charging the following raw materials into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. Then, the temperature is further raised to 325 ° C. over 3.5 hours, and then the pressure is reduced to 5 Torr (that is, 667 Pa) over 20 minutes while distilling acetic acid, excess acetic anhydride, and other low boiling points. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the mixture from a reduced pressure state to a pressurized state through normal pressure, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized to obtain pellets. The melting point of the obtained polymer was 280 ° C., and the melt viscosity at 300 ° C. was 44.0 Pa · s. The melt viscosity of the polymer was measured in the same manner as the method for measuring the melt viscosity described later.
(I) 4-Hydroxybenzoic acid (HBA); 1660 g (73 mol%)
(II) 2-Hydroxy-6-naphthoic acid (HNA); 837 g (27 mol%)
Metal catalyst (potassium acetate catalyst); 165 mg
Acylating agent (acetic anhydride); 1714 g

-Liquid crystal polyester amide resin (LCP2)
After charging the following raw materials into the polymerization vessel, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. Then, the temperature is further raised to 340 ° C. over 4.5 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 minutes while distilling acetic acid, excess acetic anhydride, and other low boiling points. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the mixture from a reduced pressure state to a pressurized state through normal pressure, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized to obtain pellets. The obtained pellets were heat-treated at 300 ° C. for 2 hours under a nitrogen stream to obtain the desired polymer. The melting point of the obtained polymer was 336 ° C., and the melt viscosity at 350 ° C. was 19.0 Pa · s. The melt viscosity of the polymer was measured in the same manner as the method for measuring the melt viscosity described later.
(I) 4-Hydroxybenzoic acid (HBA); 1380 g (60 mol%)
(II) 2-Hydroxy-6-naphthoic acid (HNA); 157 g (5 mol%)
(III) Terephthalic acid (TA); 484 g (17.5 mol%)
(IV) 4,4'-dihydroxybiphenyl (BP); 388 g (12.5 mol%)
(V) 4-acetoxyaminophenol (APAP); 126 g (5 mol%)
Metal catalyst (potassium acetate catalyst); 110 mg
Acylating agent (acetic anhydride); 1659 g

<Materials other than liquid crystal resin>
-Glass fiber: ECS03T-786H manufactured by Nippon Electric Glass Co., Ltd., chopped strand with fiber diameter of 10 μm and length of 3 mm ・ L- (+)-Arginine: A0526 manufactured by Tokyo Chemical Industry Co., Ltd.
・ Dicyandiamide: Dicyandiamide G manufactured by Nippon Carbide Industry Co., Ltd.
-Glycylglycine: G0124 manufactured by Tokyo Chemical Industry Co., Ltd.
4-Aminophenol: A0384 manufactured by Tokyo Chemical Industry Co., Ltd.

<Manufacturing of liquid crystal resin composition>
The above components were melt-kneaded at the following cylinder temperatures using a twin-screw extruder (TEX30α type manufactured by Japan Steel Works, Ltd.) at the ratio shown in Table 1 to obtain liquid crystal resin composition pellets.
[Manufacturing conditions]
Cylinder temperature:
300 ° C: In the case of a liquid crystal resin composition containing LCP1 350 ° C: In the case of a liquid crystal resin composition containing LCP2

<Melting viscosity>
The melt viscosities of the liquid crystal resin compositions of Examples and Comparative Examples were measured using the pellets. Specifically, a capillary rheometer (manufactured by Toyo Seiki Seisakusho Co., Ltd., Capillary Graph 1D: piston diameter 10 mm) is used at a temperature 10 to 30 ° C higher than the melting point of the liquid crystal resin under the condition of a shear rate of 1000 sec ^-1 . The apparent melt viscosity of was measured according to ISO 11443. An orifice having an inner diameter of 1 mm and a length of 20 mm was used for the measurement. The specific measurement temperature was 300 ° C. for the liquid crystal resin composition containing LCP1 and 350 ° C. for the liquid crystal resin composition containing LCP2. The results are shown in Table 1.

[DTUL]
The pellet was molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain a test piece for measurement (4 mm × 10 mm × 80 mm). Using this test piece, the deflection temperature under load was measured by a method compliant with ISO75-1 and ISO75-1. As the bending stress, 1.8 MPa was used. The results are shown in Table 1.
〔Molding condition〕
Cylinder temperature:
300 ° C: In the case of a liquid crystal resin composition containing LCP1 350 ° C: In the case of a liquid crystal resin composition containing LCP2 Mold temperature: 80 ° C
Injection speed: 33 mm / sec

As is clear from the results shown in Table 1, the liquid crystal resin composition of the example is excellent in fluidity at the time of melting even when the content of the high fluidizing agent is small while maintaining heat resistance. It was confirmed that.

Claims (3)

A liquid crystal resin composition containing (A) a liquid crystal resin and (B) a high fluidizing agent for a liquid crystal resin composed of an aliphatic nitrogen-containing compound having an electron-withdrawing group , wherein (B) electrons. The aliphatic nitrogen-containing compound having an attractive group is at least one liquid crystal resin composition selected from the group consisting of amino acids, oligopeptides, and dicyandiamides . The composition according to claim 1 , wherein the content of the component (B) is 0.02% by mass or more and 1.3% by mass or less in the composition. (B) A high fluidizing agent for a liquid crystal resin composed of an aliphatic nitrogen-containing compound having an electron-withdrawing group, and (B) an aliphatic nitrogen-containing compound having an electron-withdrawing group includes amino acids, oligopeptides, and A high fluidizing agent for a liquid crystal resin, which is at least one selected from the group consisting of dicyandiamide .