阅读说明：本技术 聚对苯二甲酸乙二醇酯系树脂粒子 (Polyethylene terephthalate resin particles ) 是由 原田良祐 于 2019-03-27 设计创作，主要内容包括：一种聚对苯二甲酸乙二醇酯系树脂粒子,体积平均粒径为1～100μm,所述体积平均粒径的变异系数为45％以下,具有所述体积平均粒径的2倍以上的粒径的粒子的含量为3.0体积％以下。在本发明的聚对苯二甲酸乙二醇酯系树脂粒子用于膜的情况下,膜的耐擦伤性优异,因此可以适当用作光学膜用的添加剂。(Polyethylene terephthalate resin particles having a volume average particle diameter of 1 to 100 [ mu ] m, a coefficient of variation of the volume average particle diameter of 45% or less, and a content of particles having a particle diameter of 2 times or more of the volume average particle diameter of 3.0% or less by volume. When the polyethylene terephthalate resin particles of the present invention are used in a film, the film has excellent scratch resistance and can therefore be suitably used as an additive for optical films.)

1. Polyethylene terephthalate resin particles having a volume average particle diameter of 1 to 100 [ mu ] m, a coefficient of variation of the volume average particle diameter of 45% or less, and a content of particles having a particle diameter of 2 times or more of the volume average particle diameter of 3.0% or less by volume.

2. The polyethylene terephthalate resin particle according to claim 1, wherein the intrinsic viscosity is 0.7dl/g or more and 1.5dl/g or less.

3. The polyethylene terephthalate resin particle according to claim 1 or 2, wherein the average circularity is 0.82 to 0.92.

4. The polyethylene terephthalate resin particle according to any one of claims 1 to 3, wherein a colorant and/or a release agent are not contained.

5. The polyethylene terephthalate resin particle according to any one of claims 1 to 4, which is used as an additive for an optical film.

6. A method for producing polyethylene terephthalate resin particles, which is the method for producing resin particles according to any one of claims 1 to 5,

the method comprises the following steps:

primarily pulverizing a polyethylene terephthalate raw material resin having an inherent viscosity of 0.7dl/g to 1.5dl/g into particles having a volume average particle diameter of 10 to 200 [ mu ] m by freeze-pulverization; and

the once-pulverized resin is secondarily pulverized into a volume average particle diameter of 1 to 100 [ mu ] m by a fluidized bed type jet mill.

7. A dispersion comprising the polyethylene terephthalate resin particles according to any one of claims 1 to 5 and a binder,

the polyethylene terephthalate resin particles are dispersed as a dispersoid in the binder.

8. An optical film comprising the polyethylene terephthalate resin particles according to any one of claims 1 to 5.

Technical Field

The present invention relates to polyethylene terephthalate resin particles, a method for producing the resin particles, a dispersion containing the resin particles, and an optical film containing the resin particles.

Background

The resin particles are used for modification and improvement of various materials by utilizing a larger specific surface area and a particle configuration. Examples of the main applications include compounding agents for cosmetics such as foundations, antiperspirants, and scrubs, matting agents for paints, rheology modifiers, antiblocking agents, slip agents, light diffusing agents, conductive agents, and various agents such as diagnostic test agents for medical use, and additives for molded articles such as automobile materials and building materials.

For example, patent document 1 discloses a white reflective film having a reflective layer a and a surface layer B containing particles made of a resin.

Patent document 1: japanese patent laid-open publication No. 2015-125276

However, in the film of patent document 1, the scratch resistance of the film may not be sufficient, and further improvement is required.

Disclosure of Invention

The invention provides polyethylene terephthalate resin particles which have excellent scratch resistance when used in a film. Further, the present invention addresses the problem of providing a method for producing the resin particles, a dispersion containing the resin particles, and an optical film containing the resin particles.

The invention relates to

[1] Polyethylene terephthalate resin particles having a volume average particle diameter of 1 to 100 [ mu ] m, a coefficient of variation of the volume average particle diameter of 45% or less, and a content of particles having a particle diameter of 2 times or more of the volume average particle diameter of 3.0% or less by volume.

[2] A method for producing polyethylene terephthalate resin particles according to [1], comprising: primarily pulverizing a polyethylene terephthalate raw material resin having an inherent viscosity of 0.7dl/g to 1.5dl/g into particles having a volume average particle diameter of 10 to 200 [ mu ] m by freeze-pulverization; and secondarily pulverizing the primarily pulverized resin into a volume average particle diameter of 1 to 100 μm by a fluidized bed type jet mill.

[3] A dispersion, comprising: [1] the polyethylene terephthalate resin particles and the binder are dispersed in the binder as a dispersoid.

[4] An optical film comprising the polyethylene terephthalate resin particles according to [1 ].

According to the present invention, when used in a film, polyethylene terephthalate resin particles having excellent scratch resistance of the film can be provided. Further, the present invention can provide a method for producing the resin particles, a dispersion containing the resin particles, and an optical film containing the resin particles.

Drawings

FIG. 1 is a photograph of polyethylene terephthalate resin particles of example 1.

FIG. 2 is a photograph of polyethylene terephthalate resin particles of comparative example 1.

Detailed Description

(polyethylene terephthalate resin particles)

The polyethylene terephthalate resin particles of the present invention have the following various physical properties.

(1) Various physical properties

(a) Volume average particle diameter

The volume average particle diameter of the polyethylene terephthalate resin particles of the present invention is 1 to 100 μm, preferably 20 to 60 μm, and more preferably 30 to 50 μm from the viewpoint of scratch resistance. From the viewpoint of scratch resistance, the coefficient of variation (CV value) is 45% or less, preferably 40% or less. From the viewpoint of scratch resistance, the content of particles having a particle diameter of 2 times or more the volume average particle diameter (coarse particles) is 3.0% by volume or less, preferably 2.0% by volume or less, and more preferably 1.0% by volume or less.

In the present specification, by means of a Coulter Multisizer^TM3 (measuring apparatus manufactured by Beckman Coulter) of volume average particle diameter, coefficient of variation andthere is a measurement of the content of particles having a particle diameter 2 times or more the volume average particle diameter.

Use of Multisizer according to Beckman Coulter^TM3 user manual to make a corrected aperture to perform the measurement.

In addition, the pore diameter for measurement is appropriately selected according to the size of the resin particle to be measured. Current (aperture Current) and Gain (Gain) are appropriately set according to the size of the selected aperture. For example, if an aperture having a size of 50 μm is selected, the Current (aperture Current) is set to-800 and Gain is set to 4.

The following dispersion was used as a sample for measurement: 0.1g of resin particles was dispersed in 10ml of a 0.1 mass% nonionic surfactant aqueous solution using a touch mixer (Yamato Scientific Co., Ltd., "TOUCHMIXER MT-31") and an ultrasonic cleaner (VELVO-CLEAR VS-150 ") to prepare a dispersion. During the measurement, the beaker was stirred slowly to prevent air bubbles from entering, and the measurement was terminated at the time when 10 ten thousand resin particles were measured. The volume average particle diameter of the resin particles is an arithmetic average in a volume-based particle size distribution of 10 ten thousand particles.

The coefficient of variation (CV value) of the particle diameter was calculated by the following formula.

Coefficient of variation of particle diameter ═ standard deviation of particle size distribution based on volume of resin particles ÷ volume average particle diameter of resin particles) × 100

The content of particles having a particle diameter of 2 times the volume average particle diameter is a volume-based ratio of particles having a particle diameter of 2 times or more the volume average particle diameter.

(b) Degree of circularity

The average circularity of the resin particles of the present invention is preferably 0.82 to 0.92, and more preferably 0.83 to 0.90, from the viewpoint of scratch resistance. From the viewpoint of scratch resistance, the average circularity of the particles having a particle diameter equal to or larger than the median of the area equivalent circle diameter is preferably 0.83 to 0.92, and more preferably 0.84 to 0.90. The circularity is measured by the method described in the examples described later.

(2) Polyethylene terephthalate resin

Specifically, the polyethylene terephthalate resin contains, as a resin component, 90 mol% or more, preferably 95 mol% or more, and more preferably 98 mol% or more of ethylene terephthalate units. Examples of the other components include acid components such as isophthalic acid, naphthalenedicarboxylic acid, and sebacic acid, and glycol components such as diethylene glycol and propylene glycol. More specifically, for example, there may be mentioned a vinyl isophthalate unit, an ethylene naphthalate unit, a diethyl terephthalate unit and the like. That is, the raw material polyethylene terephthalate is preferably a homopolymer, and may be a copolymer in which a dicarboxylic acid component other than terephthalic acid such as isophthalic acid and naphthalenedicarboxylic acid and/or an ethylene glycol component other than ethylene glycol such as diethylene glycol is used in an amount of 10 mol% or less based on the total dicarboxylic acid components. Further, the polymer blend may be one in which 10 mass% or less of another condensation resin is mixed with respect to the entire mass.

The intrinsic viscosity (IV value) of the polyethylene terephthalate resin particles is preferably 0.7dl/g or more, more preferably 0.75dl/g or more, and even more preferably 0.80dl/g or more from the viewpoint of reducing the particle size distribution or suppressing damage due to deformation of the resin particles, and is preferably 1.5dl/g or less, more preferably 1.45dl/g or less, and even more preferably 1.40dl/g or less from the viewpoint of suppressing damage to other members due to excessively high hardness of the resin particles or performing fine grinding.

In the present specification, the intrinsic viscosity is measured by the following method.

The intrinsic viscosity of the polyethylene terephthalate resin particles was calculated from the solution viscosity measured by heating and dissolving 0.5g of the base resin in 100ml of a mixed solution of tetrachloroethane/phenol (mass ratio) 50/50, cooling the solution, and measuring the temperature at 25 ℃.

(3) Other additives

The polyethylene terephthalate resin particles of the present invention may contain other additives as needed. Examples of the other additives include a plasticizer, a flame retardant aid, an antistatic agent, a spreading agent, a bubble control agent, a filler, a colorant, a release agent, a weather resistant agent, an anti-aging agent, a lubricant, an antifogging agent, and a perfume, but it is preferable that the coating composition does not contain a colorant and/or a release agent from the viewpoint of suppressing coating unevenness when used for coating.

(method for producing polyethylene terephthalate resin particles)

Although the method for producing the polyethylene terephthalate resin particles of the present invention is not particularly limited, a preferred embodiment includes a production method including the following primary pulverization step and secondary pulverization step.

(1) One-time crushing process

The primary grinding step is a step of coarsely grinding a polyethylene terephthalate raw material resin having an inherent viscosity of 0.7 to 1.5dl/g by freeze grinding to a volume average particle diameter of 10 to 200 [ mu ] m. From the viewpoint of improving the efficiency of the secondary grinding step, it is preferable that the coarse grinding is carried out so as to have a volume average particle diameter of 10 to 150 μm. The freeze-pulverization is carried out by a known freeze-pulverization method. That is, the polyethylene base material resin is frozen by immersing it in liquid nitrogen, and the frozen polyethylene terephthalate base material resin is put into a freezing and pulverizing machine and pulverized. The freeze-crusher may be a known freeze-crusher.

(2) Secondary crushing process

The secondary grinding step is a step of finely grinding the primarily ground resin into a volume average particle diameter of 1 to 100 μm by a fluidized bed type jet mill (back jet mill). When a fluidized bed type jet mill is used, when polyethylene terephthalate resin particles collide with each other and are finely divided, the resin particles are easily rubbed against each other, and the obtained polyethylene terephthalate resin particles are slightly rounded, and therefore, the scratch resistance is excellent. The volume average particle diameter, coefficient of variation, and content of particles having a particle diameter 2 times or more the volume average particle diameter after the micro-pulverization are the same as described above.

Thus, the polyethylene terephthalate resin particles of the present invention can be obtained.

When the polyethylene terephthalate resin particles of the present invention are used in a film, the film has excellent scratch resistance, and therefore, the polyethylene terephthalate resin particles can be suitably used as an additive for an optical film.

The polyethylene terephthalate resin particles of the present invention are also preferably provided as a dispersion. The dispersion includes the polyethylene terephthalate resin particles of the present invention and a binder, and the polyethylene terephthalate resin particles of the present invention are dispersed as a dispersoid in the binder.

Examples of the binder include acrylic resins, alkyd resins, polyester resins, polyurethane resins, chlorinated polyolefin resins, amorphous polyolefin resins, and ultraviolet-curable resins.

In the dispersion, a crosslinking agent, a solvent, a coating surface modifier, a fluidity modifier, an ultraviolet absorber, a light stabilizer, a curing catalyst, an extender pigment, a coloring pigment, a metal pigment, a mica powder pigment, a dye, and the like may be optionally contained according to the use.

The dispersion containing the polyethylene terephthalate resin particles of the present invention is preferably used for optical films such as light diffusion sheets because of its excellent scratch resistance. For example, an optical film comprising the polyethylene terephthalate resin particles of the present invention can be produced by coating the dispersion on an optical base film, and the optical film has excellent scratch resistance.

When the dispersion containing the polyethylene terephthalate resin particles of the present invention is used in an optical film, the mass ratio of the polyethylene terephthalate resin particles to the binder in the dispersion (polyethylene terephthalate resin particles/binder of the present invention) is preferably 1/10 to 1/1, and more preferably 1/5 to 1/2, from the viewpoint of obtaining an optical film having excellent light diffusion properties.