JP6715656B2 - Easy-open fiber material and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fiber material having excellent openability and a manufacturing method thereof.

Although plastic is lightweight, it is often unsuitable for use as a structural material because of its small elastic modulus. Therefore, a fiber reinforced plastic (FRP) compounded with a fiber material having a large elastic modulus such as glass fiber is used as a material having a large specific strength. As FRP, generally, glass fiber reinforced plastic (GFRP) using glass fiber as a reinforcing material and carbon fiber reinforced plastic (CFRP) using carbon fiber are known, but synthetic fiber having a large tensile strength is also used. There are also those that use natural fibers such as cellulose recently.

Some fiber length is required to reinforce plastics. It is said that the fiber length that gives ideal strength is 10 mm or more. Further, FRP is strong in tension in the fiber direction but weak in tension in the direction orthogonal to the fiber. For this reason, when high strength is required, a cloth is often woven using fibers, and a plurality of woven cloths are laminated and combined so that the directions of the fibers are different. However, even with this method, it is not easy to increase the strength in the thickness direction, and various methods have been developed in order to improve the strength.

In addition, there is a FRP manufacturing method using short cut fibers. Although this method is inferior in absolute strength to the above-mentioned method, it can be manufactured inexpensively and easily, and a structure having isotropic strength characteristics can be manufactured. Extrusion molding using pellet-shaped FRP obtained by kneading fibers and resin is applied to various products because it has a high degree of freedom in shape and the process is simple.

LFT-D (long fiber reinforced thermoplastics-direct molding method) is a manufacturing method that is expected to have the advantages of these two methods. This method is characterized in that the fibers are directly kneaded (without cutting) with the resin and molded without being processed into pellets or the like. It can be expected that a fiber length longer than the pellet size can be maintained by not forming the pellet.

However, if the resin and the fiber are not sufficiently kneaded, the fiber and the resin may not be well-adapted to each other and the fibers may be unevenly distributed, resulting in insufficient performance. On the other hand, if the kneading strength exceeds a certain limit, the fibers are broken during the kneading process, and there is a dilemma that the desired fiber length cannot be obtained.

Here, in order to increase the lower limit of the kneading strength at which breakage of the fibers proceeds, it is desirable to open the fibers in advance. Usually, when opening, the bundle of fibers (fiber bundle) is handled, tapped, or blown with an air stream. However, there is a possibility that sufficient opening may not be possible due to adhesion between fibers or friction. there were. Therefore, it is desired to improve the fiber openability.

Further, when the fiber openability is improved, slippage between single fibers occurs during the production of twisted yarns or the production of woven fabrics, and a uniform product can be obtained.

JP 2013-537124 JP

The present invention has been completed in view of the above circumstances, and an object of the present invention is to provide an easily openable fiber material having excellent openability and a method for producing the same.

(A) In order to solve the above problems, the present inventors have conducted extensive studies and completed the following invention. That is, the easily openable fiber material of the present invention comprises a fiber material composed of a single fiber having a fiber diameter of 30 μm or less, and silica having a particle diameter of 5 nm or more and 200 nm or less, which is attached to the surface of the single fiber as primary particles. And a particulate material as a main component.

It is expected that the particulate material attached as the primary particles will exist between adjacent single fibers when a plurality of single fibers are bundled. As a result, it can be expected that the existing silica acts as a roller to reduce the sliding resistance, or the existing silica serves as a wedge to prevent the fibers from adhering to each other, thereby improving the openability. Here, "the particle material is attached as primary particles" means that the particle material is discretely present when directly observed by an SEM or the like, or that a plurality of particle materials are aggregated. Even if it looks like this, it is a concept including a case where adjacent single fibers are aggregated with a force that can be easily broken when they relatively move. Whether or not “adjacent monofilaments are aggregated with a force that allows them to be easily broken when they move relative to each other” depends on whether the single fibers are bundled with the easy-open fiber material and does not contain the particulate material. It can be judged whether the resistance when sliding or separating the fibers can be reduced. The resistance when sliding or separating the single fibers can be measured by the force required when twisting or bending the single fibers after bundling them. In addition, the term "easy opening property" means that the opening property is relatively high as compared with the case where no particle material is present, and the lower limit of the value showing the opening property as an absolute value. It does not mean that the value exists.

Patent Document 1 discloses a method of impregnating continuous fibers with resin in which nanometer-sized particles are dispersed in a resin before curing and then tensile-curing the resin in a die. When the method of Patent Document 1 is adopted, the force required for pulling can be reduced.

In the invention of (1) described above, one or more of the components of (B) to (F) described below can be arbitrarily combined.
(B) The particle material has a functional group represented by the formula (1): —OSiX ¹ X ² X ³ and a functional group represented by the formula (2): —OSiY ¹ Y ² Y ³ on the surface. Hold. Since such a particle material has a good dispersibility on the surface of the single fiber, the openability can be improved.

In the above formulas (1) and (2); X ¹ is a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acryl group; and X ² and X ³ are -OSiR ₃ and -OSiY ⁴ Y ⁵ Y ⁶ are each independently selected from; ^{Y 1} is an ^{R; Y} 2, Y ³ are each selected from R and -OSiY ⁴ Y ⁵ Y ⁶ independently. Y ⁴ is R; Y ⁵ and Y ⁶ are each independently selected from R and —OSiR ₃ ; R is independently selected from an alkyl group having 1 to 3 carbon atoms. Note that any of X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ is any of adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ . You may combine with the heel -O-.
(C) The fiber material is a fiber bundle in which a plurality of the single fibers are bundled. By making the fiber bundle, it becomes possible to ensure that the particulate material is present between the surface of the single fiber and the single fiber.
(D) The amount of the particulate material is 2% or more based on the surface area of the single fiber. A high effect can be obtained by setting this range. The area of the particle material is a projected area on the surface of the single fiber.
(E) The particulate material is dispersed and attached to the surface of the single fiber. As mentioned above, the particle material is allowed to agglomerate to the extent that it breaks up due to the sliding of the single fibers, but by allowing the particle material to exist from the beginning, it becomes easy for the particle material to enter between the single fibers. Openability can be realized.
(F) The single fiber is a continuous long fiber, which is a fiber material included in the long fiber reinforced thermoplastic. The fiber material having high fiber-opening property can be opened and evenly spread in the inserted mold.
(G) A method for producing an easily-open fiber material according to the present invention, which solves the above-mentioned problems, comprises a step of spinning single fibers having a fiber diameter of 30 μm or less, a step of bundling a plurality of the single fibers, and a particle diameter of 5 nm. After the spinning step, a particle material containing silica as a main component and having a particle size of 200 nm or more is attached as primary particles to the surface of the single fiber after the spinning step.

An easily openable fiber material as disclosed in (A) above can be manufactured.
(H) Further, in the production method of (G), as the particle material, a functional group represented by the above formula (1), which can be redispersed in methyl ethyl ketone, and has a bulk density of 450 g/L or less, Those having a functional group represented by the formula (2) on the surface can be adopted.

It is the figure which observed the surface of the fiber material of Example 1 by SEM. What appears to be a white sphere is a particle material (nano silica) attached to the surface. It is the figure which observed the surface of the fiber material of the comparative example 1 with SEM. It is the schematic of the adhesion|attachment apparatus of the particulate material in the test 2 in an Example.

The easily openable fiber material and the manufacturing method thereof of the present invention will be described in detail based on the following embodiments. The easily openable fiber material of the present embodiment can be used for the above-mentioned LFT-D, and can be used for the same purpose as a normal fiber material. High openability can exhibit an advantageous effect when a product of the next stage is to be manufactured using a fiber material (easy openability) as a raw material. LFT-D uses the fiber material used when manufacturing FRP as a continuous fiber (a continuous fiber or a fiber of 50 mm or more) as it is.
(Easy opening fiber material)
The easily openable fiber material of the present embodiment has a fiber material, a particle material, and other members that are adopted as necessary.
-Fiber material Fiber material consists of single fibers. The single fiber has a fiber diameter of 30 μm or less. The fiber length is not particularly limited. It is desirable to adopt long fibers (for example, 10 mm or more, 30 mm or more, 100 mm or more, continuous long fibers).

Most monofilaments have no branching, but those having branching may also be used. The material forming the single fiber is not particularly limited, and either organic fiber or inorganic fiber may be used. For example, glass fiber, carbon fiber, polyester fiber, aramid fiber, polyethylene fiber, boron fiber, etc. may be mentioned. The surface of the single fiber may be subjected to some surface treatment such as improving the affinity with the resin. In addition, processing such as sizing may be performed.

Furthermore, the form of the fiber material may be a single fiber as it is or a plurality of fiber bundles. When forming a fiber bundle, the tows may be arranged in parallel or may be twisted. The thickness of the tow formed is not particularly limited. Further, the fiber material may be wound on a spool or may be in another form.
-Particle material The particle material adheres as primary particles to the surface of the single fiber that constitutes the fiber material. Whether or not they are attached as primary particles can be confirmed by the method as described above. The method of attaching the particle material as primary particles is not particularly limited, and examples thereof include a method of introducing the functional groups represented by Formula (1) and Formula (2) onto the surface. Particularly, it is preferable to introduce a functional group having a phenyl group as X ¹ .

The particle material has a particle size of 5 nm or more and 200 nm or less. It is particularly preferably 20 nm or less. The particle material is mainly composed of silica. Means that it contains at least 50% of the total mass as a reference when converted to the amount of "silica as a main component""SiO_2" silicon and. For example, particles made of silica crystals may be contained, or silica may be contained as a double oxide. In addition to silicon, it may contain oxygen, as well as aluminum, zirconium, zinc, iron, titanium and the like.
-Adhesion of particulate material to the surface of the fibrous material The particulate material adheres to the surface of the single fiber constituting the fibrous material as primary particles. The judgment as to whether or not the particles are attached as primary particles is as follows. First, it is judged from the appearance using a SEM photograph or the like, and it is judged that the particle material existing on the surface of the single fiber is in a dispersed state, or if it is a single layer, it is attached as primary particles. If there are two or more layers, the particle material is present uniformly, and if the surface of the single fiber is coated so that there is no local bias (aggregation), it is determined that they are attached as primary particles. To do. If there are aggregated lumps, judge whether they can be easily separated. Whether or not the particles can be separated is determined by whether or not the particles can be separated into primary particles without changing the shape of the primary particles constituting the particle material. Ultimately, if the particles can be separated in any state without changing the shape of the primary particles, it is determined that they are attached as primary particles.

The attachment may be performed by any force such as covalent bond, ionic bond, hydrogen bond, van der Waals force.

The amount of the particulate material is preferably such that the surface of the fibrous material can be covered by 1% or more based on the surface area (coverage of 1% or more). The area of the particulate material is the area when projected onto the surface of the fiber material. The coverage can be calculated from the area of the particulate material obtained by observing under a microscope.
(Method of manufacturing easily openable fiber material)
The method for producing an easily-open fiber material according to this embodiment includes a spinning step, a bundling step, and an attaching step. The spinning process is a process of spinning single fibers. The spinning of the single fiber can be appropriately performed depending on the type of the single fiber used and is not particularly limited. The bundling step is a step of bundling single fibers to form a tow. The attaching step is a step of attaching the particulate material to the surface of the single fiber spun in the spinning step. The attaching step may be before or after in relation to the bundling step.
-Adhesion step The method of adhering the particulate material to the surface of the single fiber in the adhesion step is not particularly limited. An example is given below. In the following description, when the term “fiber material” is used, it may be in a single fiber state or a bundled tow state unless otherwise specified. Further, it may be performed after forming the spool.

The fibrous material is brought into contact with the particulate material. The particulate material may be in the state as it is, fluidized by a gas, or dispersed in a liquid to form a slurry. The particulate material can be sprayed on the fibrous material after being made into a fluidized state or a slurry state. The contact with the fiber material or the spraying to the fiber material may be performed on the fiber material in a stationary state, or may be performed while moving the fiber material. An example of the movement of the fiber material is movement in the fiber length direction. For example, the fibrous material immediately after the spinning step or the bundling step may be directly drawn out and contacted or sprayed with the particulate material, and then the fibrous material may be wound. In addition, after the spool is once formed after the spinning step or the bundling step, the state of the spool or the state of pulling out from the spool can be contacted or sprayed with the particulate material. When the particle material is used as a slurry, it has a step of drying the dispersion medium used thereafter.
-Regarding the surface-treated particle material and the preparation method thereof, a method for producing the surface-treated particle material is exemplified below. The surface-treated particle material (surface-treated particle material) includes a functional group represented by the formula (1): —OSiX ¹ X ² X ³ and a formula (2): —OSiY ¹ Y ² Y ^3. Functional groups bound to the surface. Hereinafter, the functional group represented by formula (1) will be referred to as a first functional group, and the functional group represented by formula (2) will be referred to as a second functional group.

X ¹ in the first functional group is a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acryl group. X ^{2, X 3} are each -OSiR ₃ or -OSiY ⁴ Y ⁵ Y ^6. Y ⁴ is R. Y ^{5, Y 6} are each, R or -OSiR _3.

Y ¹ in the second functional group is R. Y ^{2, Y 3} are each -OSiR ₃ or -OSiY ⁴ Y ⁵ Y ^6.

The more -OSiR ₃ included in the first functional group and a second functional group, having a number R to the surface of the surface treated particulate material. The more R (alkyl group having 1 to 3 carbon atoms) contained in the first functional group and the second functional group, the more difficult the surface-treated particle material is to aggregate.

As for the first functional group, the number of R is the minimum when X ² and X ³ are each —OSiR ₃ . When X ² and X ³ are -OSiY ⁴ Y ⁵ Y ⁶ and Y ⁵ and Y ⁶ are -OSiR ₃ , the number of R is the maximum.

As for the second functional group, the number of R is the minimum when Y ² and Y ³ are each —OSiR ₃ . Further, when Y ² and Y ³ are each —OSiY ⁴ Y ⁵ Y ⁶ and each of Y ⁵ and Y ^{6 is} —OSiR ₃ , the number of R is maximum.

The number of X ¹ contained in the first functional group, the number of R contained in the first functional group, and the number of R contained in the second functional group are the abundance ratio of R and X ¹ or particles. It may be set appropriately according to the particle size of the material and the application.

Note that any of X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ is any of adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ . You may combine with the heel -O-. For example, any one of X ¹ , X ³ , Y ⁵ , and Y ⁶ of the first functional group may be X ² , X ³ , Y ⁵ , and Y ² of the first functional group adjacent to the first functional group. It may be bonded to any of Y ⁶ via —O—. Similarly, any of the second functional groups Y ² , Y ³ , Y ⁵ , and Y ⁶ is the second functional group adjacent to the second functional group Y ² , Y ³ , Y ⁵ , And Y ⁶ may be bonded to each other via —O—. Furthermore, any one of X ² , X ³ , Y ⁵ , and Y ⁶ of the first functional groups is Y ² , Y ³ , Y ^{5 of} the second functional group adjacent to the first functional group, And Y ⁶ may be bonded to each other via —O—.

In the surface-treated particle material, when the abundance ratio of the first functional group to the second functional group is 1:12 to 1:60, X ¹ and R are balanced on the surface of the surface-treated particle material. Exists well. Therefore, the surface-treated particle material in which the abundance ratio of the first functional group to the second functional group is 1:12 to 1:60 is particularly excellent in the affinity for the resin and the effect of suppressing aggregation. Further, when X ¹ is 0.5 to 2.5 per unit surface area (nm ² ) of the surface-treated particle material, a sufficient number of first functional groups are bonded to the surface of the surface-treated particle material. , R derived from the first functional group and the second functional group are also present in sufficient numbers. Therefore, also in this case, the affinity for the resin and the effect of suppressing the aggregation of the particle material are sufficiently exhibited.

In any case, R per unit surface area (nm ² ) of the surface-treated particle material is preferably 1 to 10. In this case, the balance between the number of X ^{1 and} the number of R existing on the surface of the surface-treated particle material is good, and both the affinity for the resin and the effect of suppressing aggregation of the surface-treated particle material are well balanced. To be demonstrated.

In the surface-treated particle material, it is preferable that all the hydroxyl groups existing on the surface of the particle material are substituted with the first functional group or the second functional group. When the sum of the first functional group and the second functional group is 2.0 or more per unit surface area (nm ² ) of the surface-treated particle material, in the surface-treated particle material, the surface of the particle material is It can be said that almost all of the existing hydroxyl groups are substituted with the first functional group or the second functional group.

The surface-treated particulate material has R on the surface. This can be confirmed by the infrared absorption spectrum. Specifically, when the infrared absorption spectrum of the surface-treated particle material is measured by the solid-state diffuse reflection method, there is a maximum absorption of C—H stretching vibration at 2962±2 cm ⁻¹ . Therefore, it can be confirmed by the infrared absorption spectrum whether or not it is the surface-treated particle material.

Further, as described above, the surface-treated particle material is hard to aggregate. Therefore, the surface-treated particle material can be applied to a particle material having a small particle size. For example, the surface-treated particle material can have an average particle size of about 3 nm to 5000 nm. It is preferably applied to a particle material having an average particle size of 3 to 200 nm.

It should be noted that the surface-treated particle material can be dispersed again by ultrasonic treatment even if it is slightly aggregated. Specifically, by irradiating an ultrasonic wave having an oscillation frequency of 39 kHz and an output of 500 W to a dispersion of the surface-treated particle material in methyl ethyl ketone, the surface-treated particle material can be substantially dispersed into primary particles. At this time, the ultrasonic wave irradiation time may be 10 minutes or less. Whether or not the surface-treated particle material is dispersed into primary particles can be confirmed by measuring the particle size distribution. Specifically, the methyl ethyl ketone dispersion material of this particle material is measured with a particle size distribution measuring device such as a Microtrac device, and if there is a particle size distribution of the particle material, it can be said that the surface-treated particle material is dispersed into primary particles.

Since the surface-treated particle material is hard to aggregate, it can be provided as a particle material that is not dispersed in a liquid medium such as water or alcohol. In this case, since the liquid medium is not brought in, it is preferably used as a filler for the resin material.

The surface-treated particle material preferably has a bulk density of 450 g/L or less. The bulk density in this specification is measured using an electromagnetic vibration type bulk density measuring device (MVD-86 type) manufactured by Tsutsui Rikagaku Kikai Co., Ltd. Specifically, after the sample to be measured is put into the upper 500 μm sieve as a sample tank, the sample is dispersed by electromagnetic vibration under the condition of an acceleration of 4 G through the two upper and lower 500 μm sieves and dropped into a 100 mL sample container. , The mass was measured, and the bulk density was calculated from the mass and the volume. In order to prevent the bulk density from decreasing due to its own weight, the measurement should be carried out within 1 hour after the dropping.

Preferred upper limits include 400 g/L, 350 g/L, 300 g/L and 250 g/L. A preferable lower limit is 100 g/L. By setting the bulk density to a value below these upper limits, the separation of the primary particles can be performed more reliably. Further, when the bulk density is set to a value above these lower limits, the bulk is small and handling becomes easy.

The method for surface-treating the particle material to obtain the surface-treated particle material has a step of surface-treating the particle material with a silane coupling agent and organosilazane in a liquid medium containing water (surface treatment step). The silane coupling agent has three alkoxy groups and a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acryl group (that is, X ¹ described above).

By surface-treating with a silane coupling agent, the hydroxyl groups present on the surface of the particle material are replaced with functional groups derived from the silane coupling agent. Functional group derived from the silane coupling agent has the formula (3); - represented by OSiX ¹ X ⁴ X ^5. The functional group represented by the formula (3) is referred to as a third functional group. X ¹ in the third functional group is the same as X ¹ in the functional group represented by formula (1). X ⁴ and X ⁵ are each an alkoxy group. By surface-treating with organosilazane, X ⁴ and X ⁵ of the third functional group are derived from organosilazane —OSiY ¹ Y ² Y ³ (functional group represented by formula (2), second functional group) ) Is replaced. When all the hydroxyl groups present on the surface of the particle material are not replaced with the third functional group, the hydroxyl groups remaining on the surface of the particle material are replaced with the second functional group. Therefore, on the surface of the surface-treated particle material, the functional group represented by the formula (1): —OSiX ¹ X ² X ³ (that is, the first functional group) and the formula (2): —OSiY ¹ The functional group represented by Y ² Y ³ (that is, the second functional group) is bonded. Since the molar ratio of the silane coupling agent and the organosilazane is silane coupling agent:organosilazane=1:2 to 1:10, the first functional group and the first functional group in the obtained surface-treated particle material are The abundance ratio with the functional group of 2 is theoretically 1:12 to 1:60.

In the surface treatment step, the particle material may be simultaneously surface-treated with the silane coupling agent and the organosilazane. Alternatively, the particle material may first be surface-treated with a silane coupling agent and then with organosilazane. Alternatively, the particle material may be first surface-treated with organosilazane, then with a silane coupling agent, and then with organosilazane. In any case, the amount of organosilazane may be adjusted so that all the hydroxyl groups existing on the surface of the particle material are not replaced with the second functional group. In addition, all the hydroxyl groups present on the surface of the particle material may be substituted with the third functional group, or only a part thereof may be substituted with the third functional group and the other portion may have the second functional group. It may be replaced. All X ⁴ and X ⁵ contained in the third functional group may be substituted with the second functional group.

Note that a part of the organosilazane may be replaced with the second silane coupling agent. As the second silane coupling agent, one having three alkoxy groups and one alkyl group can be used. In this case, X ⁴ and X ⁵ contained in the third functional group are replaced with the fourth functional group derived from the second silane coupling agent. The fourth functional group has the formula (4); - represented by OSiY ¹ X ⁶ X ^7. Y ¹ is the same R as ^{Y 1} in the second functional ^{group, X 6,} X ⁷ is an alkoxy group or a hydroxyl group, respectively. X ⁶ and X ⁷ contained in the fourth functional group are substituted with the second functional group derived from organosilazane or with another fourth functional group. In this case, the amount of R existing on the surface of the particle material can be further increased. When a part of the organosilazane is replaced with the second silane coupling agent, it is necessary to perform the surface treatment with the second silane coupling agent and then again perform the surface treatment with the organosilazane. This is because X ⁶ and X ⁷ contained in the fourth functional group are finally substituted with the second functional group derived from organosilazane.

When a part of the organosilazane is replaced with the second silane coupling agent, X ⁴ and X ⁵ contained in the above-mentioned first functional group are replaced with the second functional group derived from organosilazane, It is substituted with a fourth functional group derived from the second silane coupling agent. When X ⁴ and X ⁵ are substituted with a fourth functional group, X ⁶ and X ⁷ contained in the fourth functional group are substituted with a second functional group or another fourth functional group. Is replaced by If X ^6, X ⁷ contained in the fourth functional group it has been replaced by another fourth functional group, X ^6, X ⁷ contained in the fourth functional groups is substituted with the second functional group It For this reason, the second silane coupling agent may be the organosilazane which is set when the surface treatment is performed only with the first coupling agent and the organosilazane (when the organosilazane is not replaced with the second silane coupling agent). A maximum of 5a/3 mol can be replaced for the amount (a) mol. The amount of organosilazane required in this case is 8a/3 mol.

The alkoxy groups of the silane coupling agent and the second silane coupling agent are not particularly limited, but those having a relatively small number of carbon atoms are preferable, and those having 1 to 12 carbon atoms are preferable. Considering the hydrolyzability of the alkoxy group, the alkoxy group is more preferably any one of a methoxy group, an ethoxy group, a propoxy group and a butoxy group.

As the silane coupling agent, specifically, phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane. , 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3. -Aminopropyltrimethoxysilane.

The organosilazane may be any one capable of substituting the hydroxyl group existing on the surface of the particle material and the alkoxy group derived from the silane coupling agent with the above-mentioned second functional group, but one having a small molecular weight is used. preferable. Specific examples include tetramethyldisilazane, hexamethyldisilazane, pentamethyldisilazane, and the like.

Examples of the second silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane.

In the surface treatment step, a polymerization inhibitor may be added to suppress the polymerization of the silane coupling agent and the second silane coupling agent. As the polymerization inhibitor, general ones such as 3,5-dibutyl-4-hydroxytoluene (BHT) and p-methoxyphenol (methoquinone) can be used.

The surface treatment method for the particulate material may include a solidification step after the surface treatment step. The solidification step is a step of precipitating the surface-treated particulate material with a mineral acid, washing the precipitate with water, and drying it to obtain a solid particulate material. As described above, since general particle materials easily aggregate, it is very difficult to redisperse the once solidified particle material. However, since the particle material is hard to aggregate, it does not easily aggregate even if it is solidified, and it is easy to redisperse even if it aggregates. In addition, as described above, by washing the particle material with water, the particle material used for applications such as electronic parts can be easily manufactured. In the washing step, washing is preferably repeated until the electric conductivity of the extracted water of the particle material (specifically, the water obtained by immersing the particle material at 121° C. for 24 hours) becomes 50 μS/cm or less.

Examples of the mineral acid used in the solidification step include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, etc., and hydrochloric acid is particularly desirable. The mineral acid may be used as it is, but it is preferably used as a mineral acid aqueous solution. The concentration of the mineral acid in the aqueous mineral acid solution is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. The amount of the aqueous solution of mineral acid can be about 6 to 12 times based on the mass of the particulate material to be washed.

The washing with the aqueous solution of mineral acid can be performed multiple times. In the washing with the aqueous solution of mineral acid, it is desirable that the surface-treated particle material is immersed in the aqueous solution of mineral acid and then stirred. Further, it can be left in the immersed state for 1 to 24 hours, further 72 hours. When left to stand, stirring can be continued or not stirred. When cleaning in a mineral acid-containing liquid, heating at room temperature or higher can be performed.

Then, the surface-treated particle material that has been washed and suspended is collected by filtration and then washed with water. It is desirable that the water used does not contain ions such as alkali metals (for example, 1 ppm or less on a mass basis). For example, it is ion-exchanged water, distilled water, pure water, or the like. Washing with water is the same as washing with an aqueous solution of mineral acid, it is possible to disperse and suspend the surface-treated particle material and then filter, or to pass water continuously to the filtered surface-treated particle material. It is also possible to do so. The end time of washing with water may be judged by the electric conductivity of the above-mentioned extracted water, or may be the time when the concentration of alkali metal in the waste water after washing the surface-treated particle material becomes 1 ppm or less. However, the time may be when the alkali metal concentration of the extracted water becomes 5 ppm or less. When washing with water, it may be heated to room temperature or higher.

The surface-treated particulate material can be dried by a conventional method. For example, heating, leaving under reduced pressure (vacuum), and the like.

As a method of dehydrating the surface-treated particle material other than drying, to the surface-treated particle material containing water, after adding an aqueous organic solvent having a boiling point higher than that of water, a mixed material soluble in the aqueous organic solvent Can be mixed and water can be removed. As the aqueous organic solvent, propylene glycol monomethyl ether (propylene glycol-1-methyl ether, boiling point about 119°C; propylene glycol-2-methyl ether, boiling point about 130°C), butanol (boiling point 117.7°C), N-methyl- Examples include 2-pyrrolidone (boiling point: about 204° C.) and γ-butyrolactone (boiling point: about 204° C.).

The mixed material is an organic compound having a boiling point higher than that of the water-based organic solvent. Since it has a boiling point higher than that of the water-based organic solvent and water, it will eventually remain together with the surface-treated particle material. The mixed material can be made into a polymer as it is or by reacting. The mixed material can also form a matrix in which the surface-treated particulate material is dispersed. The mixed material is a compound that can be dispersed or dissolved in a state in which an aqueous organic solvent is added to the water-containing surface-treated particle material. The mixed material may be a polymer or a low molecule. The mixed material preferably has an epoxy group, an oxetane group, a hydroxyl group, a blocked isocyanate group, an amino group, a half ester group, an amic group, a carboxy group, and a carbon-carbon double bond group in its chemical structure. These functional groups are functional groups (polymerizable functional groups) that can be bonded to each other by setting suitable reaction conditions, and can improve the molecular weight of the mixed material. Suitable reaction conditions include simply heating or irradiating with light, generating reactive species such as radicals or ions (anion, cation) by irradiating with heat or light, or a reaction initiator that bonds between the functional groups. (Polymerization initiator) is added and heating or light irradiation is performed. A compound necessary for the polymerization reaction may be added as a curing agent, or a catalyst for the reaction may be added.

Preferred examples of the mixed material include a monomer that forms a polymer material by polymerization, and a polymer material modified with a polymerizable functional group as described above. For example, prepolymers such as epoxy resin, acrylic resin and urethane resin before curing are suitable.

By removing water (and also the water-based organic solvent), the surface-treated particle material can be mixed or dispersed in the mixed material.

(Evaluation of openability)
The method for evaluating the spreadability is as follows.
-Method 1: Sensitive method-Procedure 1) The tow was pulled out from the spool, and one end was fixed with an adhesive tape or a heat-shrinkable tube so that the filaments would not come apart. A test piece was obtained by cutting the tip from the fixed portion so that the length was 10 cm.
2) A metal rod (thickness: about 1 cm) was placed on the vibrating part of the vibration mixer (Voltex Geny 2) and vibrated at about 2000 rpm.
3) The fixing part in which the tows of the test piece were bundled was fixed, and the metal rod was brought into contact with about the center of the test piece to evaluate the fiber-opening property from the state in which the fiber was opened when vibrated.
-Evaluation The untreated tow was used as a standard test piece, and the degree to which the fiber opened with vibration was evaluated based on the standard test piece. It was judged that the larger the degree of progress of opening when the vibration was applied for the same time, the better the opening property. If it is worse than the standard test piece, it is "-", if it is improved, it is "+", and if there is no difference, it is "+/-". When it improved especially, it was set as "++".
-Method 2: Numericalization-Procedure 1) The tow was pulled out from the spool by about 20 cm, and both ends were fixed using adhesive tape or heat shrink tubes so that the filaments would not fall apart.
2) One end was fixed with a clamp, and the other end was pulled along the direction of the fiber so that the tow was horizontal. The pulling force was about 100 g weight.
3) The width (maximum value) of the cut portion was recorded at a portion about 10 cm from the fixed end.
-Evaluation The relative value was calculated using untreated tow as a standard test piece, and the larger the value, the better the openability.
(Test 1)
<<Example 1>>
Carbon fiber having a length of about 20 cm: CF (T-700 manufactured by Toray), and particle material having an average particle diameter of 10 nm: nanosilica (YA010C-SP3 manufactured by Admatex: X ¹ is a phenyl group) are used based on the mass of CF. Sprinkled with 0.1%. Excess nanosilica was wiped with a sponge and used as a test sample in this example.
<<Example 2>>
Particle material having an average particle size of 50 nm: Prepared in the same manner as in Example 1 except that nanosilica (YA050C-SP3 manufactured by Admatex) was used.
<<Comparative Example 1>>
Preparation was performed in the same manner as in Example 1 except that no nano silica was used.
<<Evaluation>>
The spreadability of Examples 1, 2 and Comparative Example 1 was evaluated by Method 1. In addition, observation was performed by SEM to calculate the coverage.

The test sample of Example 1 has a coverage of 31% and the spreadability is ++. The test sample of Example 2 has a coverage of 10% and the spreadability is +, and the test sample of Comparative Example 1 has a coverage of 0%. The openability was +/-. As is clear from this result, it was found that the spreadability is improved by attaching the particle material to the surface of the single fiber. Here, for reference, an SEM photograph of the test sample of Example 1 is shown in FIG. 1, and an SEM photograph of the test piece of Comparative Example 1 is shown in FIG. In FIG. 1, it can be observed that the spherical particles adhere to the surface, whereas in FIG. 2, it can be seen that the spherical particles do not adhere to the surface. Further, as is clear from FIG. 1, the particulate material is uniformly attached to the surface of the single fiber.
(Test 2)
<<Example 3>>
CF was pulled out from the roving 1 by using the apparatus as shown in FIG. 3, passed through the powder layer R made of the particulate material put in the powder box 3, and then the winding 2 was performed. The guide rollers 41 to 44 were used to guide the CF into the powder layer R.

As the particle material, nano silica having an average particle size of 10 nm (YA010C-SP3 manufactured by Admatex) was used. The winding speed was 30 m/min. The contact distance with the powder layer was 10 cm. Under these conditions, the average contact time with the powder layer was 0.2 seconds/m. The obtained sample was used as the test sample of this example.
<<Example 4>>
It was prepared in the same manner as in Example 3, except that the winding speed was 40 m/min. Under this condition, the average contact time with the powder layer is 0.15 sec/m.
<<Example 5>>
It was prepared in the same manner as in Example 3 except that the winding speed was 50 m/min. Under this condition, the average contact time with the powder layer is 0.12 sec/m.
<<Example 6>>
It was prepared in the same manner as in Example 3 except that the contact distance with the powder layer was 20 cm. Under this condition, the average contact time with the powder layer is 0.4 sec/m.
<<Comparative example 2>>
Prepared as in Example 3 except no particulate material was used.
<<Evaluation>>
The openability of each test sample of Examples 3 to 6 and Comparative Example 2 was evaluated by Methods 1 and 2. The results are shown in Table 1.

As is clear from the table, it was found that the amount (coverage) of the particulate material adhering to the surface of the single fiber can be continuously changed.

It was found that all of the test samples of Examples 3 to 6 were superior to the test sample of Comparative Example 2 in the openability by Method 2. Further, from the results of Method 2, it was found that the larger the value of the coverage, the more the openability tended to improve.

In particular, it was found that the test samples of Examples 3 and 6 were superior to the other test samples in the openability by Method 1. In the evaluation by the method 1, a significant difference from the test sample of Comparative Example 2 was recognized when the coverage was 1% or more, and a particularly remarkable difference was recognized when the coverage was 10% or more. Turns out to be the case.

In addition, the state of aggregation on the surface (state not primary particles: the particle material made of silica is treated with a silane coupling agent, and the particles are aggregated by the silane coupling agent used for the treatment) It was found that the spreadability was not sufficient when the particle material was adhered to in comparison with the case where a colleague's particle material was adhered as primary particles.

Claims (5)

A fiber material composed of single fibers having a fiber diameter of 30 μm or less,
That the attached as primary particles on the surface of the single fiber, the particle diameter is an average particle diameter of Ri der than 200nm or less 5nm is contained in the particulate material (amorphous carbon mainly composed of Der Ru silica or 50nm or less 10 nm, And excluding those fused to the fiber material) ,
Have a,
The particulate material is
Formula (1): having a functional group represented by -OSiX ¹ X ² X ³ and a functional group represented by Formula (2): -OSiY ¹ Y ² Y ³ on the surface,
The easily openable fiber material in which the amount of the particulate material is 10% or more based on the surface area of the single fiber. (In the above formulas (1) and (2); X ¹ is a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group or an acrylic group; X ² , X ³ selected Y 2, ^{Y 3} are each independently from R and -OSiY ⁴ Y ⁵ Y ^6; is -OSiR ₃ and -OSiY ⁴ Y ⁵ Y ⁶ are each independently selected from; ^{Y 1} is R .Y ⁴ is an R; ^{Y 5} and ^{Y 6} is selected from R and -OSiR ₃ independently;. R is independently selected from alkyl groups of 1 to 3 carbon atoms Incidentally, ^{X 2} , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ are any of adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ , and -O-. You may combine them with.) The easily openable fiber material according to claim 1 , wherein the fiber material is a fiber bundle in which a plurality of the single fibers are bundled. The easily spreadable fiber material according to claim 1 or 2 , wherein the particle material is dispersed and attached to the surface of the single fiber. The monofilament is a continuous filament,
Easy-openability fibrous material according to any one of claims 1 to 3 is a fiber material with the long-fiber-reinforced thermoplastics. A step of spinning a single fiber having a fiber diameter of 30 μm or less,
Bundling a plurality of the single fibers,
A step of mean particle size particle size Ri der than 200nm or less 5nm is to deposit particulate material mainly composed of Der Ru silica or 50nm or less 10nm as primary particles in the dry state to the surface of the single fiber after the spinning process ,
Have a,
The particulate material is
Can be redispersed in methyl ethyl ketone, and
Has a bulk density of 450 g/L or less,
Formula (1): of an easy-open fiber material having a functional group represented by -OSiX ¹ X ² X ³ and a functional group represented by Formula (2): -OSiY ¹ Y ² Y ³ on the surface. Production method. (In the above formulas (1) and (2); X ¹ is a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group or an acrylic group; X ² , X ³ selected Y 2, ^{Y 3} are each independently from R and -OSiY ⁴ Y ⁵ Y ^6; is -OSiR ₃ and -OSiY ⁴ Y ⁵ Y ⁶ are each independently selected from; ^{Y 1} is R .Y ⁴ is an R; ^{Y 5} and ^{Y 6} is selected from R and -OSiR ₃ independently;. R is independently selected from alkyl groups of 1 to 3 carbon atoms Incidentally, ^{X 2} , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ are any of adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ , and -O-. You may combine them with.)