JP2015025033A - Composite of nonwoven fabric and resin, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonwoven fabric resin composite combining high tear strength and a low linear thermal expansion coefficient, and a method for producing the same.SOLUTION: Provided is a composite obtained by incorporating a resin into a nonwoven fabric including the first resin in which the number-average fiber width is 2 nm or more to less than 1,000 nm and the second fiber in which the number-average fiber width is 1,000 to 100,000 nm and also the number-average fiber length is 0.1 to 20 mm.

Description

  The present invention relates to a composite of a nonwoven fabric and a resin including two types of fibers having different number average fiber widths, and a method for producing the same.

  In recent years, attention has been focused on the application of reproducible natural fibers due to the substitution of petroleum resources and the growing environmental awareness. Among natural fibers, cellulose fibers, particularly wood-derived cellulose fibers (pulp) are widely used mainly as paper products. Most cellulose fibers used for paper have a width of 10 to 50 μm. Paper (sheet) obtained from such cellulose fibers is opaque and is widely used as printing paper. On the other hand, when the cellulose fiber is treated (beating, pulverizing) with a refiner, kneader, sand grinder or the like, and the cellulose fiber is refined (microfibril), transparent paper (glassine paper or the like) is obtained. Conventionally, nonwoven fabrics composed of cellulose fibers have been added to papers, books, and the like as paper by adding sizing agents, paper strength enhancing agents, and the like. Furthermore, the use of nonwoven fabrics composed of cellulose fibers for a filter, a power storage element, a battery or a separator of a capacitor has been studied using permeability to gas or liquid.

  Patent Document 1 describes a non-woven fabric obtained by papermaking cellulose fibers having an average fiber diameter of 0.1 to 20 μm and cellulose nanofibers having an average fiber diameter of less than 100 nm. This is intended to provide a cellulose fiber nonwoven fabric composed of cellulose fibers having a fine fiber diameter of micron order or less and having high mechanical strength and heat resistance.

  Patent Document 2 describes a nonwoven fabric containing cellulose fibers having an average fiber diameter of 0.1 to 50 μm and polyolefin fibers having an average fiber diameter of 1.5 μm or less and having a thickness of 20 μm or less. The purpose of this is to provide a nonwoven fabric that can achieve both air permeability and mechanical strength even if it is thin.

  On the other hand, Patent Document 3 describes a nonwoven fabric sheet made of short fibers, a reinforcing material, and an elastic polymer. The short fiber is composed of an acrylonitrile-based copolymer composed of 50 to 95% by weight of acrylonitrile and at least one other monomer, and acrylic fibers A and B having at least two different fiber diameters are used. The fiber diameters of the acrylic fibers A and B are such that A is 0.1 μm or more and less than 7 μm, B is 10 μm or more and less than 18 μm, and the mixing ratio is A / B = 40/60 to 80/20. It is a feature. Patent document 3 aims at providing the nonwoven fabric sheet for synthetic leather which gives animal hair tone or a tone-like texture by using the fiber from which fineness differs, or using a different kind of fiber.

JP 2012-36517 A JP 2012-36518 A JP 2000-248471 A

  This invention made it the subject which should be solved to provide the nonwoven fabric resin composite which has both high tear strength and a low linear thermal expansion coefficient, and its manufacturing method.

  The present inventors diligently studied to solve the above problems. First, a dispersion containing a first fiber having a number average fiber width of 2 nm or more and less than 1000 nm and a second fiber having a number average fiber width of 1000 nm or more and 100000 nm or less and a number average fiber length of 0.1 to 20 mm. The liquid was filtered and the nonwoven fabric in the wet paper state after filtration was dried. Then, it discovered that the composite_body | complex of the nonwoven fabric and resin which has both high tear strength and a low linear thermal expansion coefficient can be manufactured by compounding resin with the nonwoven fabric manufactured above. The present invention has been completed based on these findings.

That is, according to the present invention, the following inventions are provided.
(1) A first fiber having a number average fiber width of 2 nm or more and less than 1000 nm and a second fiber having a number average fiber width of 1000 nm or more and 100,000 nm or less and a number average fiber length of 0.1 to 20 mm are contained. A composite containing a resin in a nonwoven fabric.
(2) The composite according to (1), wherein the tear strength is 20 mN or more.
(3) The composite according to (1) or (2), wherein the linear thermal expansion coefficient is 70 ppm / K or less.

(4) The composite according to any one of (1) to (3), wherein the total light transmittance is 80% or more and the haze is 10 to 80%.
(5) The composite according to any one of (1) to (4), wherein the basis weight is 50 to 200 g / m ² .
(6) The composite according to any one of (1) to (5), wherein the fiber content is 10 to 70% by mass.

(7) The composite according to any one of (1) to (6), wherein the mass ratio of the first fiber to the second fiber is 99.9 / 0.1 to 50/50.
(8) The composite according to any one of (1) to (7), wherein the mass ratio of the first fiber to the second fiber is 99/1 to 60/40.
(9) The composite according to any one of (1) to (8), wherein the number average fiber width of the first fibers is 2 nm or more and less than 800 nm.
(10) The composite according to any one of (1) to (9), wherein the first fiber is a cellulose fiber and the second fiber is a polyester fiber.

(11) A first fiber having a number average fiber width of 2 nm or more and less than 1000 nm and a second fiber having a number average fiber width of 1000 nm or more and 100,000 nm or less and a number average fiber length of 0.1 to 20 mm are contained. The method according to any one of (1) to (10), including a step of filtering the dispersion and drying the non-woven fabric in the wet paper state after filtration, and a step of combining the resin with the non-woven fabric. A method for producing the composite.

  ADVANTAGE OF THE INVENTION According to this invention, the composite_body | complex of the nonwoven fabric and resin which have both high tear strength and a low linear thermal expansion coefficient, and its manufacturing method are provided.

  Hereinafter, the present invention will be described in more detail. Note that the descriptions of materials, methods, and numerical ranges described in this specification are not intended to be limited to the materials, methods, and numerical ranges, and other materials, methods, and numerical ranges are not intended. It does not exclude the use of such as.

  The composite of the present invention includes a first fiber having a number average fiber width of 2 nm to less than 1000 nm, and a second fiber having a number average fiber width of 1000 nm to 100,000 nm and a number average fiber length of 0.1 to 20 mm. And a non-woven fabric containing a resin.

(1) Nonwoven fabric The nonwoven fabric used in the present invention is a first fiber having a number average fiber width of 2 nm or more and less than 1000 nm, a number average fiber width of 1000 nm or more and 100,000 nm or less, and a number average fiber length of 0.1 to 20 mm. Containing a second fiber.

[First fiber]
The type of the first fiber used in the present invention is not particularly limited as long as it is a fine fiber having a number average fiber width of 2 nm or more and less than 1000 nm. For example, it may be fine cellulose fibers, fine fibers other than fine cellulose fibers, or a mixture of fine cellulose fibers and fine fibers other than fine cellulose fibers. Particularly preferably, the first fiber is a cellulose fiber.

  Details of the fine cellulose fibers will be described later. Examples of fibers other than fine cellulose fibers include, but are not limited to, semi-synthetic fibers and regenerated fibers such as inorganic fibers, organic fibers, and synthetic fibers. Examples of inorganic fibers include, but are not limited to, glass fibers, rock fibers, and metal fibers. Examples of organic fibers include, but are not limited to, fibers derived from natural products such as carbon fibers, chitin, and chitosan. Examples of synthetic fibers include, but are not limited to, nylon, pinilone, vinylidene, polyester, polyolefin (eg, polyethylene, polypropylene, etc.), polyurethane, acrylic, polyvinyl chloride, aramid, and the like. Semi-synthetic fibers include but are not limited to acetate, triacetate, promix and the like. Examples of the regenerated fiber include, but are not limited to, rayon, cupra, polynosic rayon, lyocell, and tencel. When the fine cellulose fibers and fine fibers other than the fine cellulose fibers are mixed and used, the fine fibers other than the fine cellulose fibers can be subjected to treatments such as chemical treatment and defibration treatment as necessary. When fine fibers other than fine cellulose fibers are subjected to treatment such as chemical treatment and defibration treatment, fine fibers other than fine cellulose fibers are mixed with fine cellulose fibers and then subjected to treatment such as chemical treatment and defibration treatment. Can be applied. Alternatively, the fine fibers other than the fine cellulose fibers can be mixed with the fine cellulose fibers after being subjected to treatment such as chemical treatment and defibration treatment. When the fine fibers other than the fine cellulose fibers are mixed, the addition amount of the fine fibers other than the fine cellulose fibers in the total amount of the fine cellulose fibers and the fine fibers other than the fine cellulose fibers is not particularly limited. The addition amount is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and particularly preferably 20% by mass or less.

<Fine cellulose fiber>
In the present invention, fine cellulose fibers obtained by chemically treating and defibrating cellulose raw materials may be used as the first fibers.
Examples of the cellulose raw material include paper pulp, cotton pulp such as cotton linter and cotton lint, non-wood pulp such as hemp, straw, and pagas, cellulose isolated from sea squirts and seaweed, etc., but are not particularly limited. . Among these, paper pulp is preferable in terms of availability, but is not particularly limited. Paper pulp includes hardwood kraft pulp (bleached kraft pulp (LBKP), unbleached kraft pulp (LUKP), oxygen bleached kraft pulp (LOKP), etc.), softwood kraft pulp (bleached kraft pulp (NBKP), unbleached kraft pulp) (NUKKP, oxygen bleached kraft pulp (NOKP), etc.), sulfite pulp (SP), chemical pulp such as soda pulp (AP), semi-chemical pulp (SCP), semi-chemical pulp such as chemiground wood pulp (CGP) In addition, mechanical pulp such as groundwood pulp (GP) and thermomechanical pulp (TMP, BCTMP), non-wood pulp made from cocoons, cocoons, hemp, kenaf, etc., deinked pulp made from waste paper, It is not limited. Among these, kraft pulp, deinked pulp, and sulfite pulp are preferable because they are more easily available, but are not particularly limited. A cellulose raw material may be used individually by 1 type, and may be used in mixture of 2 or more types.

  The number average fiber width of the fine cellulose fibers is 2 nm or more and less than 1000 nm, and more preferably the number average fiber width is 2 nm or more and less than 800 nm. The fine cellulose fibers may be cellulose fibers or rod-like particles that are much thinner than the pulp fibers normally used in papermaking applications. The fine cellulose fiber is an aggregate of cellulose molecules including a crystal part, and its crystal structure is type I (parallel chain). The number average fiber width of the fine cellulose fibers can be measured by observing with an electron microscope. When the average fiber width of the fine cellulose fiber is less than 2 nm, the physical properties (strength, rigidity, dimensional stability) as the fine cellulose fiber are not exhibited because the cellulose molecule is dissolved in water. The fact that the fine cellulose fiber has a type I crystal structure has a typical peak in a diffraction profile obtained from a wide-angle X-ray diffraction photograph using CuKα (λ = 1.5418Å) monochromatized with graphite. Can be identified. In other words, the diffraction profile can be identified by having typical peaks at two positions near 2θ = 14 to 17 ° and 2θ = 22 to 23 °. Moreover, the measurement of the fiber width by electron microscope observation of a fine cellulose fiber is performed as follows. An aqueous suspension of fine cellulose fibers having a concentration of 0.05 to 0.1% by mass is prepared, and the suspension is cast on a carbon film-coated grid subjected to a hydrophilic treatment to obtain a sample for TEM observation. When a wide fiber is included, an SEM image of the surface cast on glass may be observed. Observation with an electron microscope image is performed at a magnification of 1000 times, 5000 times, 10000 times, or 50000 times depending on the width of the constituent fibers. However, the sample, observation conditions, and magnification are adjusted to satisfy the following conditions.

(1) One straight line X is drawn at an arbitrary location in the observation image, and 20 or more fibers intersect the straight line X.
(2) A straight line Y perpendicular to the straight line is drawn in the same image, and 20 or more fibers intersect the straight line Y.

  The width of the fiber that intersects with the straight line X and the straight line Y is visually read from the observation image that satisfies the above conditions. In this way, at least three sets of images of the surface portion that do not overlap each other are observed, and the width of the fiber intersecting with the straight line X and the straight line Y is read for each image. Thus, at least 20 × 2 × 3 = 120 fiber widths are read. The average fiber width of fine cellulose fibers is the average value of the fiber widths read in this way.

  Although the fiber length of a fine cellulose fiber is not specifically limited, 1-1000 micrometers is preferable, 5-800 micrometers is more preferable, and 10-600 micrometers is especially preferable. When the fiber length is less than 1 μm, it is difficult to form a fine fiber sheet. If it exceeds 1000 μm, the slurry viscosity of the fine fibers becomes very high and it becomes difficult to handle. The fiber length can be obtained by image analysis using TEM, SEM, or AFM.

<Chemical treatment>
The method of chemical treatment of cellulose raw materials or other fiber raw materials (inorganic fibers, organic fibers, synthetic fibers, semi-synthetic fibers, regenerated fibers, etc.) is not particularly limited as long as it is a method capable of obtaining fine fibers. Examples include, but are not limited to, ozone treatment, enzyme treatment, or treatment with a compound capable of forming a covalent bond with a functional group in cellulose or a fiber raw material.

  As an example of the ozone treatment, there is a method described in JP 2010-254726 A, but it is not particularly limited. Specifically, after the fiber is treated with ozone, it is dispersed in water, and the resulting aqueous dispersion of the fiber is pulverized.

  As an example of the enzyme treatment, the method described in Japanese Patent Application No. 2012-115411 (all the contents described in Japanese Patent Application No. 2012-115411 shall be cited in the present specification) can be mentioned, but it is particularly limited. Not. Specifically, the fiber raw material is treated with an enzyme at least under a condition where the ratio of the enzyme EG activity to the CBHI activity is 0.06 or more.

Although the following method is mentioned as a process by the compound which can form a covalent bond with the functional group in a cellulose or fiber raw material, It does not specifically limit.
(A) treatment with a compound having a quaternary ammonium group described in JP2011-162608A;
(B) a method using a carboxylic acid compound described in Japanese Patent Application No. 2012-24457; and (c) an oxo acid containing a phosphorus atom in its structure, a polyoxo acid described in Japanese Patent Application No. 2011-252649 Or at least one compound selected from the salts thereof;
The contents described in Japanese Patent Application Nos. 2012-24457 and 2011-252649 are all cited in the present specification.

  The treatment with a compound having a quaternary ammonium group described in JP 2011-162608 A is a method of reacting a hydroxyl group in a fiber with a cationizing agent having a quaternary ammonium group to cation-modify the fiber. It is.

  The method of using the carboxylic acid compound described in Japanese Patent Application No. 2012-24457 is as follows. First, a fiber raw material is treated with at least one carboxylic acid compound selected from the group consisting of a compound having two or more carboxy groups, an acid anhydride of a compound having two or more carboxy groups, and derivatives thereof. Then, a carboxy group is introduced into the fiber raw material. After the completion of the carboxy group introduction step, an alkali treatment step of treating the fiber raw material into which the carboxy group has been introduced with an alkaline solution is performed.

  The method described in Japanese Patent Application No. 2011-252649 treats a fiber raw material with at least one compound selected from oxo acids, polyoxo acids or salts thereof containing a phosphorus atom in the structure (hereinafter referred to as compound A). It is a method to do. Examples of this method include a method of mixing a powder or an aqueous solution of Compound A into a fiber raw material, a method of adding an aqueous solution of Compound A to a fiber raw material slurry, and the like. Compound A includes, but is not limited to, phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, polyphosphonic acid or esters thereof. Moreover, these may take the form of a salt. Examples of the compound having a phosphate group include phosphoric acid, sodium phosphate sodium phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, sodium metaphosphate, and potassium phosphate. Potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, potassium metaphosphate, and ammonium phosphates, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triphosphate Examples thereof include ammonium, ammonium pyrophosphate, and ammonium metaphosphate, but are not particularly limited.

<Defibration processing>
Cellulose raw materials or other fiber raw materials (inorganic fibers, organic fibers, synthetic fibers, semi-synthetic fibers, regenerated fibers, etc.) are refined by subjecting them to a defibrating treatment, and the number average fiber width is 2 nm or more and less than 1000 nm. Can be obtained. In the defibrating treatment step, the raw material obtained by the chemical treatment can be defibrated using a defibrating apparatus to obtain a fine fiber dispersion.

  As the defibrating apparatus, a wet pulverizing apparatus or the like can be used as appropriate. For example, grinder (stone mill type grinder), high pressure homogenizer, ultra high pressure homogenizer, high pressure collision type grinder, ball mill, disk type refiner, conical refiner, twin screw kneader, vibration mill, homomixer under high speed rotation, ultrasonic Examples thereof include a disperser and a beater, but are not limited thereto.

[Secondary fiber]
The type of the second fiber used in the present invention is not particularly limited as long as the number average fiber width is 1000 nm or more and 100,000 nm or less and the number average fiber length is 0.1 to 20 mm. Examples thereof include, but are not particularly limited to, cellulose fibers, inorganic fibers, organic fibers, synthetic fibers, semi-synthetic fibers, regenerated fibers and the like described above in relation to the first fibers. Of the above, the second fibers are particularly preferably synthetic fibers, and most preferably polyester.

[Mass ratio of first fiber to second fiber]
In the present invention, the mass ratio between the first fiber and the second fiber is not particularly limited. That is, the mass ratio of the first fiber and the second fiber can be appropriately set according to the type of the first fiber and the second fiber, and used. Preferably, the mass ratio of the first fiber to the second fiber is 99.9 / 0.1 to 50/50, and more preferably 99/1 to 60/40. When the mass ratio of the second fibers is less than 0.1, the specific tear strength is lowered, and when the mass ratio of the second fibers exceeds 50, the tensile strength tends to be lowered, which is not preferable.

[Nonwoven fabric]
The nonwoven fabric used in the present invention preferably has a specific tear strength of 3.0 mN · m ² / g or more and a tensile strength of 10 MPa or more. The specific tear strength is, for example, 3.0 to 50 mN · m ² / g, preferably 4.0 to 45 mN · m ² / g, more preferably 5.0 to 40 mN · m ² / g, but is not particularly limited. The tensile strength is, for example, 10 to 200 MPa, preferably 10 to 180 MPa, more preferably 15 to 150 MPa, further preferably 20 to 100 MPa, and particularly preferably 20 to 80 MPa, but is not particularly limited.

The basis weight of the nonwoven fabric is not particularly limited, preferably 3~200g / ^{m 2,} more preferably from 10 to 100 g / ^{m 2,} more preferably from 20 to 60 g / ^{m 2.}

  Non-woven fabric has additives depending on the application, such as sizing agent, wax, inorganic filler, colorant, stabilizer (antioxidant, heat stabilizer, ultraviolet absorber, etc.), plasticizer, antistatic agent, You may contain a flame retardant.

  The thickness of the nonwoven fabric is not particularly limited, and is generally about 1 to 100 μm. A nonwoven fabric may laminate | stack a some nonwoven fabric according to the objective.

[Method for producing nonwoven fabric]
The manufacturing method of a nonwoven fabric is not specifically limited, For example, it can manufacture by mixing 1st fiber and 2nd fiber and making paper, such as wet papermaking or dry papermaking.

  The wet papermaking can be performed by a usual method. For example, the papermaking may be performed using a wet papermaking machine equipped with a manual papermaking machine or a perforated plate. Dry papermaking can also be made using conventional methods such as airlaid and card manufacturing.

  For example, in the present invention, a non-woven fabric can be produced by wet papermaking using a dispersion containing first fibers and second fibers. The dispersion liquid is a liquid containing first fibers, second fibers, and a dispersion medium. As the dispersion medium, water or an organic solvent can be used, but from the viewpoint of handleability and cost, only water is preferable, but it is not particularly limited. Even when an organic solvent is used, it is preferably used in combination with water, but is not particularly limited. Organic solvents used in combination with water include alcohol solvents (methanol, ethanol, propanol, butanol, etc.), ketone solvents (acetone, methyl ethyl ketone, etc.), ether solvents (diethyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, etc.), acetate solvents A polar solvent such as a solvent (such as ethyl acetate) is preferable, but the solvent is not particularly limited thereto. Although the solid content concentration in a dispersion liquid is not specifically limited, It is preferable that it is 0.05-10 mass%, and it is more preferable that it is 0.1-5 mass%. A nonwoven fabric can be manufactured by filtering the above dispersion and drying the nonwoven fabric in the wet paper state after filtration.

(2) About resin The composite of this invention is manufactured by making resin mentioned above contain. The mixing ratio of the nonwoven fabric and the resin is not particularly limited, but is preferably 1:99 to 99: 1, more preferably 5:95 to 95: 5, and particularly preferably 10:90 to 90:10.

  The resin is not particularly limited, and a thermoplastic resin, a thermosetting resin, a photocurable resin, or a resin based on silsesquioxane having an organic-inorganic hybrid structure may be used.

As thermoplastic resins, styrene resins, acrylic resins, aromatic polycarbonate resins, aliphatic polycarbonate resins, aromatic polyester resins, aliphatic polyester resins, aliphatic polyolefin resins, cyclic olefin resins, polyamides Resin, polyphenylene ether resin, thermoplastic polyimide resin, polyacetal resin, polysulfone resin, amorphous fluorine resin, and the like, but are not limited thereto.

  Examples of thermosetting resins include epoxy resins, acrylic resins, oxetane resins, phenol resins, urea resins, melamine resins, unsaturated polyester resins, silicon resins, polyurethane resins, allyl ester resins, diallyl phthalate resins, and the like. Not limited.

  Examples of the photocurable resin include precursors such as an epoxy resin, an acrylic resin, and an oxetane resin, but are not limited thereto.

The resin may be used alone, or two or more different resins may be used.
Of the thermoplastic resin, thermosetting resin, and photocurable resin described above, the photocurable resin is most preferable.

  Examples of the curing agent for the thermosetting resin include, but are not limited to, polyfunctional amines, polyamides, acid anhydrides, and phenol resins. Examples of the curing catalyst for the thermosetting resin include imidazole and the like, but are not particularly limited thereto. The said hardening | curing agent and a curing catalyst can also be used independently, and can also use 2 or more types.

  Examples of the method for curing the composite of the nonwoven fabric and the resin by containing the resin in the nonwoven fabric and curing it include a method of curing by heat and a method of curing by radiation irradiation. However, it is not limited to these. Examples of radiation include, but are not limited to, infrared light, visible light, and ultraviolet light. In the case of a method of curing by heat, for example, a thermal polymerization initiator may be used, and any method that can be cured can be used without particular limitation.

(3) About a composite in which a resin is contained in a nonwoven fabric The shape of the composite of the present invention in which a resin is contained in a nonwoven fabric is not particularly limited, such as a sheet shape, a solid shape, a spherical shape, or a particle shape, and may have a curved surface. It may be good or an irregular shape. The thickness is not particularly limited. Further, when the composite is a sheet, a plurality of sheets can be laminated.

The tear strength of the composite of the present invention is not particularly limited, but is preferably 20 mN or more. The tear strength is, for example, 20 mN to 300 mN, more preferably 25 mN to 300 mN, and further preferably 30 mN to 200 mN.
The linear thermal expansion coefficient of the composite of the present invention is not particularly limited, but is preferably 70 ppm / K or less. A linear thermal expansion coefficient is 60 ppm / K or less, for example, More preferably, it is 50 ppm / K or less, More preferably, it is 40 ppm / K or less, Most preferably, it is 30 ppm / K or less.

The total light transmittance of the composite of the present invention is not particularly limited, but is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more, and particularly preferably 80% or more. . The upper limit of the total light transmittance is not particularly limited, and may be 100% or 99% or less.
The haze of the composite of the present invention is not particularly limited, but is preferably 10 to 80%, more preferably 20 to 80%, still more preferably 30 to 70%, and particularly preferably 40 to 60%. is there.

Although the basic weight of the composite_body | complex of this invention is not specifically limited, Preferably it is 50-200 g / m < ² >, More preferably, it is 50-150 g / m < ² >.
Although the fiber content rate in the composite_body | complex of this invention is not specifically limited, Preferably it is 10-70 mass%, More preferably, it is 20-60 mass%.

The composite of the present invention can be used for displays such as liquid crystal displays, plasma displays, organic EL displays, field emission displays, rear projection televisions, and the like. Further, the composite of the present invention can be used for touch panels, solar cell substrates, front plates, color filter substrates, and the like. In particular, the plastic substrate for display using the composite of the present invention can replace the composite of the present invention for the glass application used in these displays, and effects such as weight reduction, flexibility, and resistance to cracking are obtained. It is done.
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1
(1) Production of non-woven fabric Softwood bleached kraft pulp (NBKP) was beaten with a double disc refiner until the irregular freeness reached 100 ml to obtain a pulp dispersion (A) having a concentration of 2%. The number average fiber length at this time was 0.30 mm, and the number average fiber width was 24400 nm. This was diluted with ion-exchanged water so that the concentration was 0.2%, and subjected to a micronization process three times at a processing pressure of 120 MPa with a high-pressure homogenizer “Panda Plus 2000” manufactured by NiroSoavi, and a dispersion containing cellulose fine fibers (B ) The number average fiber width at this time was 130 nm.

  A polyester short fiber “N801” (number average fiber width 20000 nm, number average fiber length 5.0 mm) manufactured by Nihon Ester Co., Ltd. with respect to the cellulose fine fiber-containing dispersion (B) is obtained. 2 was mixed. The mixture was stirred for 5 minutes so that the whole amount was sufficiently mixed with a three-one motor to obtain a cellulose fine fiber / polyester short fiber mixed dispersion (C).

The cellulose fine fiber / polyester short fiber mixed dispersion (C) was adjusted so that the finished basis weight of the nonwoven fabric was 40.0 g / m ² . This is cast on a filter bottle in which an Advantech PTFE membrane is placed on an advantech Buchner funnel type glass filter “KG-90” having a sintered size of 30 to 50 μm, and filtered while sucking with an aspirator. It was. The non-woven fabric in the form of wet paper thus prepared is made of Toethylene Chemical Co., Ltd. diethylene glycol dimethyl ether (DEGDME; trade name “Hisolv MDM”, molecular weight 134, boiling point 162 ° C., surface tension 28 N / m) 100 parts of solid content of the nonwoven fabric. 2400 parts was added. After DEGDME was suction filtered, the nonwoven fabric in a wet paper state was dried while being pressurized to 0.1 MPa with a cylinder dryer heated to 105 ° C. to obtain a nonwoven fabric (D) containing cellulose fine fibers / short polyester fibers. The basis weight of the cellulose fine fiber / polyester short fiber-containing nonwoven fabric (D) obtained through the above procedure was 35.1 g / m ² .

(2) 100 ml of acetic anhydride was impregnated with acetylated cellulose fine fiber / polyester short fiber-containing nonwoven fabric (D) and heated at 90 ° C. for 7 hours. Then, after thoroughly washing with distilled water and finally immersing in 2-propanol for 10 minutes, press-dried at 120 ° C. and 0.14 MPa for 5 minutes to obtain a nonwoven fabric (E) containing acetylated cellulose fine fibers and polyester short fibers. Obtained. The basis weight of the acetylated cellulose fine fiber / polyester short fiber-containing nonwoven fabric (E) was 39.4 g / m ² .

(3) Resin composite Acetylated cellulose fine fiber / polyester short fiber-containing nonwoven fabric (E) was mixed with 96 parts by weight of bis (methacryloyloxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane, pentaerythritol tetrakis ( (β-thiopropionate) 4 parts by weight, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BASF Lucillin TPO) 0.05 part by weight, benzophenone 0.05 part by weight was impregnated with a solution, Overnight under reduced pressure. This was sandwiched between two glass plates and irradiated under an irradiance of 400 mW / cm ² at a line speed of 7 m / min using an electrodeless mercury lamp (“D bulb” manufactured by Fusion UV Systems). The irradiation dose at this time was 0.12 J / cm ² . This operation was performed twice by inverting the glass surface. The temperature of the glass surface after ultraviolet irradiation was 25 ° C.

Next, irradiation was performed under an irradiance of 1900 mW / cm ^{2 at} a line speed of 2 m / min. The radiation dose at this time was 2.7 J / cm ² . This operation was performed 8 times by inverting the glass surface. The temperature of the glass surface after ultraviolet irradiation was 44 ° C. The irradiation dose was 21.8 J / cm ² . After the ultraviolet irradiation was completed, the glass plate was removed and heated in a vacuum oven at 190 ° C. for 4 hours to obtain a fiber resin composite. In addition, the irradiance of ultraviolet rays was measured at 23 ° C. by using an ultraviolet ray illuminance meter “UV-M02” manufactured by Oak Seisakusho and using an attachment “UV-35”. The basis weight of the obtained fiber resin composite was 102.9 g / m ² .

(Example 2)
In Example 1 (1), the polyester short fiber “N801” manufactured by Nippon Ester Co., Ltd. was mixed with the cellulose fine fiber-containing dispersion (B) so that the weight ratio of cellulose / polyester short fiber was 95/5. Operations other than those described above were the same, and a nonwoven fabric was obtained. The basis weight of the obtained nonwoven fabric was 35.3 g / m ² . Thereafter, a fiber resin composite material was obtained in the same manner as in the case of (2) acetylation and (3) resin composite in Example 1. The basis weight of the non-woven fabric containing acetylated cellulose fine fibers and polyester short fibers was 38.8 g / m ² , and the basis weight of the fiber resin composite was 94.9 g / m ² .

Example 3
In Example 1 (1), the polyester short fiber “N801” manufactured by Nippon Ester Co., Ltd. was mixed with the cellulose fine fiber-containing dispersion (B) so that the weight ratio of cellulose / polyester short fiber was 90/10. Operations other than those described above were the same, and a nonwoven fabric was obtained. The basis weight of the obtained nonwoven fabric was 34.9 g / m ² . Thereafter, a fiber resin composite material was obtained in the same manner as in the case of (2) acetylation and (3) resin composite in Example 1. The basis weight of the acetylated cellulose fine fiber / polyester short fiber-containing nonwoven fabric was 39.6 g / m ² , and the basis weight of the fiber resin composite was 99.9 g / m ² .

Example 4
In Example 1 (1), the polyester short fiber “N801” manufactured by Nippon Ester Co., Ltd. is mixed with the cellulose fine fiber-containing dispersion (B) so that the cellulose / polyester short fiber has a weight ratio of 80/20. Operations other than those described above were the same, and a nonwoven fabric was obtained. The basis weight of the obtained nonwoven fabric was 35.2 g / m ² . Thereafter, a fiber resin composite material was obtained in the same manner as in the case of (2) acetylation and (3) resin composite in Example 1. The basis weight of the non-woven fabric containing acetylated cellulose fine fibers and polyester short fibers was 39.7 g / m ² , and the basis weight of the fiber resin composite was 101.1 g / m ² .

(Example 5)
In Example 1 (1), the polyester short fiber “N801” manufactured by Nippon Ester Co., Ltd. was mixed with the cellulose fine fiber-containing dispersion (B) so that the weight ratio of cellulose / polyester short fiber was 70/30. Operations other than those described above were the same, and a nonwoven fabric was obtained. The basis weight of the obtained nonwoven fabric was 35.5 g / m ² . Thereafter, a fiber resin composite material was obtained in the same manner as in the case of (2) acetylation and (3) resin composite in Example 1. The basis weight of the acetylated cellulose fine fiber / polyester short fiber-containing nonwoven fabric was 39.8 g / m ² , and the basis weight of the fiber resin composite was 100.8 g / m ² .

(Example 6)
In Example 1 (1), the polyester short fiber “N801” manufactured by Nippon Ester Co., Ltd. was mixed with the cellulose fine fiber-containing dispersion (B) so that the weight ratio of cellulose / polyester short fiber was 60/40. Operations other than those described above were the same, and a nonwoven fabric was obtained. The basis weight of the obtained nonwoven fabric was 34.7 g / m ² . Thereafter, a fiber resin composite material was obtained in the same manner as in the case of (2) acetylation and (3) resin composite in Example 1. The basis weight of the acetylated cellulose microfiber polyester staple fiber containing non-woven fabric is 39.9 g / ^{m 2,} the basis weight of the fiber resin composite was 100.6 g / ^{m 2.}

(Comparative Example 1)
In Example 1 (1), other fibers were not mixed with the fine cellulose fiber-containing dispersion (B), and the finished basis weight of the nonwoven fabric was adjusted to 40.0 g / m ² . Thereafter, a nonwoven fabric was obtained in the same manner as in Example 1 (1). The basis weight of the obtained nonwoven fabric was 34.8 g / m ² . Thereafter, a fiber resin composite material was obtained in the same manner as in the case of (2) acetylation and (3) resin composite in Example 1. The basis weight of the non-woven fabric containing acetylated cellulose fine fibers was 40.5 g / m ² , and the basis weight of the fiber resin composite was 102.4 g / m ² .

<Anomaly Freeness>
The irregular freeness used as a reference in adjusting the pulp dispersion liquid (A) in Example 1 is the freeness measured according to JIS P 8121 except that the amount of collected pulp was 0.3 g / L.

<Evaluation method>
The fiber resin composites produced in Examples 1 to 6 and Comparative Example 1 were evaluated according to the following evaluation methods. The evaluation results are shown in Table 1.

(1) Haze of fiber resin composite material In accordance with JIS standard K7136, the haze value by C light was measured using a haze meter manufactured by Suga Test Instruments.
(2) Total light transmittance of fiber resin composite material Based on JIS standard K7105, the total light transmittance by C light was measured using the haze meter by Suga Test Instruments.
(3) Linear thermal expansion coefficient of fiber resin composite material The obtained fiber resin composite was cut into 3 mm width x 40 mm length by a laser cutter. Using a TMA120 manufactured by SII, this was stretched in a tension mode at 20 mm between chucks, a load of 10 g, and a nitrogen atmosphere at a temperature of 5 ° C./min. At 180 ° C. to 25 ° C. at 5 ° C./min. At 25 ° C to 180 ° C, 5 ° C / min. The linear thermal expansion coefficient was determined from the measured value from 60 ° C. to 100 ° C. at the time of the second temperature increase.
(4) Tear strength test of fiber resin composite material Measured according to JIS K 7128-2 except that the test piece length was 30 mm, the width was 20 mm, the upper semicircular radius was 10 mm, and the cut was 20 mm.

  As is apparent from Table 1, in Examples 1 to 6, composites having high tear strength and low linear thermal expansion coefficient were obtained. On the other hand, in Comparative Example 1, a composite having reduced tear strength was obtained.

Claims (11)

Resin a non-woven fabric containing a first fiber having a number average fiber width of 2 nm or more and less than 1000 nm, and a second fiber having a number average fiber width of 1000 nm or more and 100,000 nm or less and a number average fiber length of 0.1 to 20 mm. A composite containing The composite according to claim 1, which has a tear strength of 20 mN or more. The composite according to claim 1 or 2, wherein the coefficient of linear thermal expansion is 70 ppm / K or less. The composite according to any one of claims 1 to 3, wherein the total light transmittance is 80% or more and the haze is 10 to 80%. Basis weight of 50 to 200 g / ^{m 2,} the composite body according to any one of claims 1 to 4. The composite according to any one of claims 1 to 5, wherein the fiber content is 10 to 70% by mass. The composite according to any one of claims 1 to 6, wherein a mass ratio of the first fiber to the second fiber is 99.9 / 0.1 to 50/50. The composite according to any one of claims 1 to 7, wherein a mass ratio of the first fiber to the second fiber is 99/1 to 60/40. The composite according to any one of claims 1 to 8, wherein the number average fiber width of the first fibers is 2 nm or more and less than 800 nm. The composite according to any one of claims 1 to 9, wherein the first fibers are cellulose fibers and the second fibers are polyester fibers. A dispersion containing a first fiber having a number average fiber width of 2 nm or more and less than 1000 nm, and a second fiber having a number average fiber width of 1000 nm or more and 100,000 nm or less and a number average fiber length of 0.1 to 20 mm. The composite according to any one of claims 1 to 10, comprising a step of producing a nonwoven fabric by filtering and drying the nonwoven fabric in a wet paper state after filtration, and a step of compounding a resin with the nonwoven fabric. Manufacturing method.