CN104152151B - A kind of liquid-crystal composition with smectic phase - Google Patents

Abstract

The invention discloses a kind of liquid-crystal composition with smectic phase, this liquid-crystal composition comprises the first component, the second component and the 3rd component; Wherein the first component is compound shown in formula I, and the second component is compound shown in formula II, the 3rd component comprise in the mixture of compound shown in formula III, formula IV and formula V one or more.The liquid-crystal composition clearing point that the present invention prepares is high, and raw material is easy to get, with low cost, stable performance.

Description

A kind of liquid crystal composition with smectic phase

technical field

The invention belongs to the field of liquid crystal materials, and in particular relates to a liquid crystal composition with a smectic phase, which is applied to a liquid crystal device.

Background technique

Energy conservation has become the theme of today's society, and the demand for energy-saving materials is also rising. Liquid crystal materials have broad development space in the field of energy-saving materials due to their good photoelectric properties. Liquid crystal materials have both liquid fluidity and solid order characteristics. Liquid crystals can be classified into nematic liquid crystals, cholesteric liquid crystals, and smectic liquid crystals according to their arrangement. Among them, the smectic phase liquid crystal has the structural characteristics of interlayer order and intralayer disorder. This feature determines the good stability of the smectic phase liquid crystal. The smectic phase liquid crystal can achieve a scattering state or transmit through an external field such as an electric field. state, and this state can still be maintained after the external field is removed, that is, no continuous input from the external field is required. Therefore, using smectic liquid crystals in fields such as display materials, utilizing the feature that smectic liquid crystals can maintain a certain state can save a lot of energy.

In practical applications, liquid crystal materials with excellent performance in various aspects are mostly obtained by mixing small molecule liquid crystals, such as liquid crystal mixtures with characteristics such as large dielectric coefficient, high birefringence, low viscosity, and high-definition bright spots. But so far, there are still no rules to follow for various liquid crystal mixing methods.

Contents of the invention

The object of the present invention is to provide a liquid crystal composition with a smectic phase, which has the characteristics of low system cost and high clearing point. The method of the invention adopts the compounding of cyanide liquid crystal, and further prepares the liquid crystal composition with smectic phase.

The liquid crystal composition includes a second component, and the liquid crystal composition further includes a first component or a third component, or a mixture thereof;

The first component is one or more of the compounds shown in formula I, wherein R1 is _an alkyl group containing 8 to 12 carbon atoms;

The second component is one or more of the compounds shown in formula II, wherein R ₂ is an alkyl group containing 8-16 carbon atoms.

The third component includes one or more of the compounds shown in formula III, formula IV and formula V, wherein X is phenyl or cyclohexyl, Y is cyano or a compound containing 1 to 6 carbon atoms Alkoxy, R ₃ , R ₄ , and R ₆ are independently alkyl groups containing 1 to 6 carbon atoms, R ₅ is an alkyl group containing 7 to 12 carbon atoms, and R ₇ is an alkyl group containing 1 to 6 carbon atoms Alkyl or hydrogen atom;

Preferably, the liquid crystal composition includes the first component: 0%-80%, the second component: 20%-80%, and the third component: 0%-30% by mass percentage.

Preferably, the liquid crystal composition includes compounds represented by formula I, formula II, formula III, formula IV and formula V, wherein, R ₁ is an alkyl group containing 8 to 12 carbon atoms, R ₂ is an alkyl group containing 8 An alkyl group with ~16 carbon atoms, X is phenyl or cyclohexyl, Y is a cyano group or an alkoxy group containing 1 to 6 carbon atoms, R ₃ , R ₄ , and R ₆ independently contain 1 to 6 An alkyl group of carbon atoms, R5 is an alkyl group containing ₇ to 12 carbon atoms, and _R7 is an alkyl group containing 1 to 6 carbon atoms or a hydrogen atom.

More preferably, the mass fraction of the compound shown in formula I is 59% to 62%, the mass fraction of the compound shown in formula II is 24% to 26%, the compound shown in formula III is 5% to 6%, and the compound shown in formula IV is 2% to 3%, and the mass fraction of the compound represented by formula V is 5% to 6%.

The invention discloses a liquid crystal composition with a smectic phase. The liquid crystal composition has the advantages of readily available raw materials, low cost, high-definition bright spots and stable performance, and is of great significance for the industrialization of liquid crystal energy-saving devices. The present invention utilizes the properties of liquid crystal materials and selects liquid crystal materials of different structures for mixing, which greatly reduces the cost of raw materials for liquid crystal energy-saving devices and promotes the industrialization process, which is of great significance.

Detailed ways

The meanings and test conditions of the symbols involved in the following examples are as follows:

S→SmA represents the phase transition temperature from crystallinity to smectic A phase;

SmA→N represents the phase transition temperature from smectic A phase to nematic phase;

ClearingPoint means clearing point;

Viscosity means viscosity, which is tested with a viscometer at 20°C;

Δn represents optical anisotropy, Δn=n _o -n _e , wherein, n _o is the refractive index of ordinary light, and _ne is the refractive index of extraordinary light, tested by Abbe refractometer, the test condition is 589nm, 20°C;

Δε represents dielectric anisotropy, Δε=ε _∥ -ε _⊥ , where ε _∥ is the dielectric constant parallel to the molecular axis, ε _⊥ is the dielectric constant perpendicular to the molecular axis, tested using HP4284A, the test condition is 25°C , 100hz;

V _10,25 means the threshold voltage, the test condition is 25°C;

V _90,25 means the saturation voltage, the test condition is 25°C.

Example 1

A liquid crystal composition was prepared according to the compounds and mass fractions in Table 1, and performance tests were performed on the obtained smectic phase liquid crystal composition.

Table 1, the component ratio of the smectic phase liquid crystal composition of embodiment 1

The properties of the above liquid crystal composition are shown in Table 2.

Table 2 Embodiment 1 liquid crystal composition properties

Example 2

The liquid crystal composition was configured according to the compounds and mass fractions in Table 3, and the performance test was performed on the obtained smectic phase liquid crystal composition.

The component ratio of the smectic phase liquid crystal composition of table 3 embodiment 2

The properties of the above liquid crystal composition are shown in Table 4.

Table 4 Embodiment 2 liquid crystal composition properties

Example 3

A liquid crystal composition was prepared according to the compounds and mass fractions in Table 5, and performance tests were performed on the obtained smectic phase liquid crystal composition.

The component ratio of the smectic phase liquid crystal composition of table 5 embodiment 3

The properties of the above liquid crystal composition are shown in Table 6.

Table 6 Embodiment 3 liquid crystal composition properties

Claims (1)

1. have a liquid-crystal composition for smectic phase, it is characterized in that, described liquid-crystal composition comprises second component, and described liquid-crystal composition also comprises three components, or the mixture of the first component and three components;

The first described component is one or more in compound shown in formula I, wherein, and R ₁it is the alkyl containing 8 ~ 12 carbon atoms;

Described second component is compound shown in formula II, wherein, and R ₂it is the alkyl containing 8 ~ 16 carbon atoms;

Described three components comprises one or more in compound shown in formula III, formula IV and formula V, and wherein, X is phenyl or cyclohexyl, and Y is cyano group or the alkoxyl group comprising 1 ~ 6 carbon atom, R ₃, R ₄, R ₆be independently the alkyl containing 1 ~ 6 carbon atom, R ₅for the alkyl containing 7 ~ 12 carbon atoms, R ₇for the alkyl containing 1 ~ 6 carbon atom or hydrogen atom;

compound shown in III is 5% ~ 6%, and compound shown in formula IV is 2% ~ 3%, and compound quality mark shown in formula V is 5% ~ 6%.