JP2014015512A - Cellulose fiber-containing resin composition - Google Patents

Abstract

In a fiber-containing resin composition using cellulose fiber as a fibrous reinforcing material and olefin resin as a resin, it can be easily manufactured industrially, has excellent strength and elastic modulus, and further has haze and linear expansion. A cellulose fiber-containing resin composition having a low coefficient is provided.
A cellulose fiber-containing resin composition comprising cellulose fibers and an olefin resin. The cellulose constituting the cellulose fiber has a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms. The olefin resin preferably contains a polar group-containing olefin resin.
[Selection figure] None

Description

  The present invention relates to a cellulose fiber-containing resin composition containing cellulose fibers and an olefin resin, and pellets thereof.

  Materials in which strength and rigidity are greatly improved by blending various fibrous reinforcing materials with resins are widely used in fields such as electric / electronics, machinery, automobiles, and building materials. Among these, olefin-based resins are used in a wide range of fields because they are inexpensive and excellent in mechanical properties, heat resistance, chemical resistance, water resistance, and the like.

  Conventionally, glass fiber has been widely used as a fibrous reinforcing material to be blended with a resin. However, the glass fiber has high specific gravity although high rigidity is achieved, and there is a limit to the weight reduction. Moreover, since glass fiber is an inorganic substance, when it incinerates, ash content increases and there also exists a fault that it is not suitable for thermal recyclability.

  As the fibrous reinforcing material, polyester fiber and polyamide fiber are lightweight, but have a drawback that the mechanical reinforcing effect is not sufficient. Aramid fibers can be reduced in weight and increased in rigidity and are suitable for thermal recycling. However, the aramid fibers have low fluidity during processing and have disadvantages such as impact resistance. Furthermore, natural fibers have light weight and thermal recyclability, but the reinforcing effect is not sufficient.

  On the other hand, in recent years, composite materials using fine cellulose fibers have been studied extensively. It is known that cellulose has a low linear expansion coefficient, high elasticity, and high strength when combined with a resin because of its extended chain crystal. However, since the cellulose fiber is hydrophilic, it is difficult to disperse in the resin, and various improvements have been made.

  For example, Patent Document 1 discloses that the elastic modulus of a composite film with cellulose acetate is improved by introducing an acetyl group into cellulose fibers. However, the cellulose acetate disclosed in Patent Document 1 is originally It has a high affinity with cellulose fibers, and it is difficult to apply this technology to hydrophobic resins.

  Patent Document 2 discloses a method of forming a fine cellulose fiber into a nonwoven fabric and impregnating it with a thermoplastic resin, followed by drying, or cooling after defoaming to form a composite with a resin. However, when a cellulose nonwoven fabric and an olefin resin are combined, it is industrially necessary to dissolve the olefin resin in a solvent or to impregnate the cellulose nonwoven fabric as a melt because a large amount of heat energy is required. Have difficulty. Further, even when heated to a high temperature and dissolved in a solvent or melted, there is a problem that they are not substantially impregnated into cellulose fibers.

Japanese National Patent Publication No. 11-513425 JP 2006-316253 A

  The present invention is a fiber-containing resin composition using cellulose fibers as a fibrous reinforcing material and an olefin resin as a resin, which can be easily manufactured industrially, has excellent strength and elastic modulus, and further has haze and wire. It is an object to provide a cellulose fiber-containing resin composition having a low expansion coefficient.

  As a result of intensive studies by the present inventors, it was found that the above problems can be solved by using a cellulose fiber having a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms, and the present invention has been achieved. .

  That is, the present invention is a fiber-containing resin composition comprising cellulose fibers and an olefin resin, and the cellulose constituting the cellulose fibers is a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms. A cellulose fiber-containing resin composition having a group and a pellet containing the cellulose fiber-containing resin composition.

  According to the present invention, there is provided a cellulose fiber-containing resin composition comprising cellulose fibers and an olefin resin, which can be easily produced industrially, has excellent strength and elastic modulus, and further has low haze and linear expansion coefficient. be able to.

  Hereinafter, embodiments of the present invention will be specifically described. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not specified by these contents. .

  The cellulose fiber-containing resin composition of the present invention is a fiber-containing resin composition containing cellulose fibers and an olefin resin, and the cellulose constituting the cellulose fibers is a linear or branched aliphatic carbonization having 5 or more carbon atoms. It has a functional group having a hydrogen chain.

[Cellulose fiber]
First, the cellulose fiber contained in the cellulose fiber-containing resin composition of the present invention (hereinafter sometimes referred to as “cellulose fiber of the present invention”) will be described. The cellulose fiber of the present invention may be any of the cellulose-containing material described in detail below, a cellulose fiber material purified from the cellulose-containing material, and a fine cellulose fiber defibrated from the cellulose fiber material. It only needs to have a functional group having a chain or branched aliphatic hydrocarbon chain. As the cellulose fiber, only cellulose itself may be used, or cellulose partially containing impurities may be used.

  However, the cellulose fiber contained in the cellulose fiber-containing resin composition of the present invention usually has a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms introduced into the cellulose fiber raw material. , Fine cellulose fibers obtained by defibration, or fine cellulose fibers obtained by defibration of cellulose fiber raw material, with functional groups having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms It is preferable that

Accordingly, the fiber diameter of the cellulose fiber of the present invention is usually 2 nm or more, preferably 4 nm or more, preferably 1500 nm or less, and 1200 nm or less in terms of the number average fiber diameter, like the fiber diameter of fine cellulose fibers. Preferably, 1000 nm or less is more preferable, 800 nm or less is further preferable, 500 nm or less is particularly preferable, and 400 nm or less, 300 nm or less, and 100 nm or less are more preferable.
The number average fiber diameter of the cellulose fibers is preferably as small as possible. However, in order to develop a low linear expansion coefficient and a high elastic modulus, it is important to maintain the crystallinity of cellulose, and it is preferably 2 nm or more.

  The number average fiber diameter of cellulose fibers is usually observed with SEM, TEM, etc., and a diagonal line in the photograph is drawn, and 12 fibers are randomly extracted in the vicinity to remove the thickest and thinnest fibers. 10 points are measured, and the measured values are averaged.

In addition, the cellulose fiber contained in the cellulose fiber-containing resin composition of the present invention preferably has 1.6 mol% or more of a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms. It is more preferable to have 3 mol% or more, and particularly preferable to have 6.6 mol% or more. Further, the content of the functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms in the cellulose fiber is preferably 66 mol% or less, more preferably 50 mol% or less, and 33 mol% or less. It is particularly preferred that
The content of the functional group referred to here corresponds to the proportion of all hydroxyl groups in the cellulose modified with the functional group, that is, the chemical modification rate described later. The amount of the functional group of the cellulose fiber can be measured by a titration method described later.

<Cellulose-containing material>
Examples of cellulose-containing materials include woods such as conifers and hardwoods (wood flour, etc.), cotton such as cotton linter and cotton lint, pomace such as sugar cane and sugar radish, bast fibers such as flax, ramie, jute and kenaf Leaf fibers such as sisal and pineapple, petiole fibers such as abaca and banana, fruit fibers such as coconut palm, stem-derived fibers such as bamboo Natural cellulose such as encapsulates. These natural celluloses are preferable because of high crystallinity and high elastic modulus. In particular, cellulose fibers obtained from plant-derived materials are preferred.

Bacterial cellulose is preferred in that it can be easily obtained with a fine fiber diameter. Cotton is also preferable in that it is easy to obtain a fine fiber diameter, and more preferable in terms of easy acquisition of raw materials.
In addition, wood of conifers and hardwoods with fine fiber diameters can be obtained, and it is the largest amount of biological resources on the planet. It is a sustainable resource that produces about 70 billion tons per year. Therefore, it contributes greatly to the reduction of carbon dioxide that affects global warming, which is advantageous from an economic point of view.

  When wood is used as the cellulose fiber of the present invention, it is preferably used after being crushed into a state of wood chips or wood flour. This crushing may be performed at any timing before, after or after the purification treatment described later.

<Cellulose fiber raw material>
The cellulose fiber raw material is obtained by purifying the cellulose-containing material by a usual method.
For example, the cellulose-containing material can be obtained by degreasing with benzene-ethanol or an aqueous sodium carbonate solution, followed by delignification treatment with chlorite (Wise method) and dehemicellulose treatment with alkali. In addition to the Wise method, a method using peracetic acid (pa method), a method using a peracetic acid persulfuric acid mixture (pxa method), and the like are also used as purification methods. Moreover, you may perform a bleaching process etc. further suitably.

  As a dispersion medium used for the purification treatment, water is generally used, but an aqueous solution of an acid or base or other treatment agent may be used, and in this case, it may be finally washed with water. .

  The degree of purification of the cellulose fiber raw material obtained by refining the cellulose-containing material is not particularly defined, but it is preferable that the fat content of the cellulose fiber raw material is less because the fat and oil and lignin are less and the cellulose component content is higher.

The cellulose fiber raw material may be obtained by a general method for producing chemical pulp, for example, a method for producing kraft pulp, salified pulp, alkali pulp, or nitrate pulp.
That is, as a cellulose fiber raw material, you may use hardwood kraft pulp, softwood kraft pulp, hardwood sulfite pulp, softwood sulfite pulp, hardwood bleached kraft pulp, softwood bleached kraft pulp, linter pulp and the like.

The content of the cellulose component in the cellulose fiber raw material is preferably 80% by weight or more, more preferably 90% by weight or more, and still more preferably 95% by weight or more.
The cellulose component of the cellulose fiber raw material can be classified into a crystalline α-cellulose component and an amorphous hemicellulose component. It is preferable that the content of crystalline α-cellulose is high because a low linear expansion coefficient, a high elastic modulus, and a high strength can be easily obtained when a cellulose fiber-containing resin composition is obtained. The crystalline α-cellulose content of the cellulose fiber raw material can be determined by measuring an insoluble part in the concentrated alkaline solution in accordance with ISO 699-1982. The crystalline α-cellulose content of the cellulose fiber raw material of the present invention is preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 85% by weight or more. If the crystalline α-cellulose content increases the purification degree of the cellulose fiber raw material, a highly pure cellulose fiber raw material exceeding 98% by weight can be obtained. Since the extreme refining (purification) of the cellulose fiber raw material may reduce the yield of the cellulose fiber raw material, the content of crystalline α-cellulose in the cellulose fiber raw material should be 95% by weight or less. Is more practical and preferred.

Although the fiber diameter of the cellulose fiber raw material is not particularly limited, it is usually 1 μm to 10 mm as the number average fiber diameter, but from the viewpoint of defibration efficiency and handleability, the number average fiber diameter is 50 μm to 1 mm. It is preferable that it is 10 μm to 0.5 mm. In order to obtain such a fiber diameter, for example, a mechanical treatment such as cutting or crushing may be performed on the cellulose-containing material. The mechanical treatment may be performed at any time before, during or after the purification treatment. For example, an impact pulverizer or a shear pulverizer may be used before the purification treatment, and a refiner or the like may be used during the purification treatment or after the treatment.
For example, when a chip or the like having a size of several centimeters is refined, it is preferable to perform a mechanical treatment with a disintegrator such as a refiner or a beater to make it about several mm.
In addition, the number average fiber diameter of the cellulose fiber raw material which passed through general refinement | purification is about 50 micrometers normally.

<Introduction of a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms>
The cellulose fiber used in the present invention is characterized in that the cellulose constituting the cellulose fiber has a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms.

  The functional group may be introduced into the cellulose-containing material described above or may be introduced into the cellulose fiber raw material. In addition, the cellulose fiber raw material may be introduced into fine cellulose fibers obtained by performing the defibrating treatment described in detail below, and the sheet-like cellulose fibers obtained by papermaking the fine cellulose fibers or cellulose fiber raw materials. May be introduced.

  For example, when introducing the functional group into a cellulose fiber raw material, a cellulose fiber raw material in a water-containing state (hereinafter sometimes referred to as “cellulose fiber raw material dispersion”) is used, and the dispersion and the functional group are used. A compound capable of introducing a group (hereinafter referred to as a “chemically modified agent”, a cellulose fiber into which a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms is introduced is referred to as a “chemically modified cellulose fiber”. The functional group can be introduced by mixing and reacting.

  Alternatively, the functional group may be introduced by contacting a gas of a compound capable of introducing the functional group with a dry cellulose fiber raw material to cause a reaction or the like.

  The functional group to be introduced is not particularly limited as long as it has a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms, but is usually a functional group generated by a reaction with a hydroxyl group of cellulose. .

  The number of carbon atoms of the aliphatic hydrocarbon chain is usually 5 or more, preferably 6 or more, more preferably 7 or more, preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less. Setting the number of carbon atoms of the aliphatic hydrocarbon chain within this range is preferable because the dispersibility and affinity of the cellulose fiber for the olefin resin are particularly good.

The carbon number of the functional group itself having the aliphatic hydrocarbon chain is preferably 5 or more, more preferably 6 or more, preferably 30 or less, more preferably 25 or less, and still more preferably 20 or less.
The molecular weight of the functional group is preferably 87 or more, more preferably 100 or more, preferably 500 or less, more preferably 400 or less, and still more preferably 350 or less.

Specifically, examples of the functional group having an aliphatic hydrocarbon chain include an acyl group, an isocyanate group, and an alkyl group.
Examples of the acyl group include a hexanoyl group, a heptanoyl group, an octanoyl group, a nonanoyl group, a decanoyl group, an undecanoyl group, a lauroyl group, a myristoyl group, a palmitoyl group, a stearoyl group, a nicotinoyl group, and an isonicotinoyl group.
Examples of the isocyanate group include a pentylisocyanoyl group, a hexylisocyanoyl group, a cyclopentylisocyanoyl group, and a cyclohexylisocyanoyl group.
Examples of the alkyl group include a pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, myristyl group, palmityl group, stearyl group and the like.
Among them, an acyl group or an alkyl group is preferable because it is easily dispersed in the olefin resin, and an acyl group is preferably an octanoyl group, a lauroyl group, or a stearoyl group, and an alkyl group is preferably an octyl group, a decyl group, a palmityl group, or a stearyl group. .

  Only 1 type of this functional group may be introduce | transduced with respect to the cellulose fiber, or 2 or more types may be introduce | transduced.

  The method for introducing the functional group is not particularly limited, and for example, there is a method of reacting a cellulose fiber raw material or fine cellulose fiber with a chemical modifier. Although there are no particular limitations on the reaction conditions, a solvent, a catalyst, or the like may be used, or heating, decompression, or the like may be performed as necessary.

  Examples of the chemical modifier include one or more selected from the group consisting of acids, acid anhydrides, alcohols, halogenating reagents, isocyanates, alkoxysilanes, and the like. When combining 2 or more types, two or more different functional groups can be introduced into the cellulose fiber.

Examples of the acid include saturated fatty acids such as hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, palmitic acid, and stearic acid.
Examples of the acid anhydride include hexanoic anhydride.
Examples of the halogenating reagent include hexanoyl halide, heptanoyl halide, octanoyl halide, nonanoyl halide, decanoyl halide, lauroyl halide, palmitoyl halide, stearoyl halide and the like.
Examples of the alcohol include pentanol, hexanol, heptanol, octanol, nonanol, decanol, dodecanol, cetanol, octadecanol and the like.
Examples of the isocyanate include pentyl isocyanate, hexyl isocyanate, cyclopentyl isocyanate, cyclohexyl isocyanate, and the like.
Of these chemical modifiers, halogenating reagents are preferred.

Hereinafter, a method for introducing a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms using a cellulose fiber raw material dispersion will be described.
When the cellulose fiber raw material dispersion is used, the dispersion medium of the cellulose fiber raw material dispersion is usually water, an organic solvent, or the like. Although it does not specifically limit as an organic solvent, For example, dimethylformamide, toluene, a pyridine, etc. are mentioned. When a water-insoluble organic solvent is used as the organic solvent, if the cellulose fiber raw material after purification is in an aqueous dispersion or water-containing state, it can be replaced with a water-soluble organic solvent and then replaced with an organic solvent used in the reaction. preferable.

  In addition, it is preferable that the cellulose fiber raw material density | concentration in a cellulose fiber raw material dispersion is 1 to 50 weight%.

  For the introduction of the functional group, a chemical modifier is added to and mixed with the cellulose fiber raw material dispersion. The chemical modifier is preferably used in an amount of 10 to 2000% by weight based on the cellulose fiber raw material. By setting it as this range, the reaction rate to a cellulose fiber raw material becomes favorable.

  Also when using the gas of a chemical modifier, it is preferable to use 10-2000 weight% of a chemical modifier with respect to a cellulose fiber raw material. By setting it as this range, the reaction rate to a cellulose fiber raw material becomes favorable.

  After adding the chemical modifier to the cellulose fiber raw material dispersion, the reaction solution is mixed and reacted by stirring or the like. The reaction temperature is 0 to 200 ° C., and the reaction time is preferably about 10 minutes to 20 hours. After the reaction, the chemically modified cellulose fiber raw material is washed with alcohol, acetone, water or the like to obtain a dispersion or cake of the chemically modified cellulose fiber.

The amount of the functional group (chemical modification rate) in the cellulose fiber raw material into which the functional group is thus obtained is preferably 1.6 mol% or more, like the cellulose fiber of the present invention. More preferably, it is 3.3 mol% or more, and particularly preferably 6.6 mol% or more. Further, it is preferably 66 mol% or less, more preferably 50 mol% or less, and particularly preferably 33 mol% or less.
The chemical modification rate here refers to the proportion of all hydroxyl groups in cellulose that have been modified with a functional group having a straight or branched aliphatic hydrocarbon chain having 5 or more carbon atoms. It can be measured by the titration method.

これを解いていくと、以下の通りである。

0.05 g of dry cellulose is precisely weighed, and 1.5 ml of ethanol and 0.5 ml of distilled water are added thereto. This is left to stand in a hot water bath at 60 to 70 ° C. for 30 minutes, and then 2 ml of 0.5 M aqueous sodium hydroxide solution is added. After leaving this in a 60-70 degreeC hot water bath for 3 hours, it ultrasonically shakes for 30 minutes with an ultrasonic cleaner. This is titrated with 0.2 M hydrochloric acid standard solution using phenolphthalein as an indicator.
Here, from the amount Z (ml) of 0.2 M hydrochloric acid aqueous solution required for titration and the amount Z ₀ (ml) of 0.2 N hydrochloric acid aqueous solution required for titration of the blank sample (= sample without dry cellulose), The amount Q (mol) of the functional group is determined by the formula.
Q (mol) = (Z ₀ −Z) × 0.2 / 1000
The relationship between the number of moles Q of this functional group and the chemical modification rate X (mol%) is calculated by the following formula (cellulose = (C ₆ O ₅ H ₁₀ ) _n = (162.14) _n , repeated Number of hydroxyl groups per unit = 3, molecular weight of OH = 17). In the following, T is the molecular weight of the functional group.

Solving this, it is as follows.

<Defibration processing>
In the present invention, the cellulose fiber raw material introduced with the functional group and the olefin resin are mixed to obtain the cellulose fiber-containing resin composition of the present invention. Usually, at the time of this mixing, the cellulose fiber raw material is defibrated to become fine cellulose fibers.

Further, before mixing with the olefin resin, the cellulose fiber raw material into which the functional group is introduced may be defibrated to form fine cellulose fibers, and the fine cellulose fibers may be mixed with the olefin resin.
The defibration in that case is usually performed in a cellulose fiber raw material dispersion. When the functional group is introduced into the cellulose fiber raw material using a gas of a compound capable of introducing the functional group, the functional group is dispersed in a dispersion medium.
In addition, this fine cellulose fiber is corresponded to the cellulose fiber of this invention, and a fiber diameter is as above-mentioned.

  When defibration is performed in the cellulose fiber raw material dispersion, the solid content concentration as the cellulose fiber raw material is 0.1% by weight or more, preferably 0.2% by weight or more, particularly 0.3% by weight or more, and 10% by weight. In the following, it is particularly preferable to use a cellulose fiber raw material dispersion of 6% by weight or less.

  If the solid content concentration in the cellulose fiber raw material dispersion used in this defibrating process is too low, the amount of liquid will increase with respect to the amount of cellulose to be treated, resulting in poor efficiency, and if the solid content concentration is too high, the fluidity will be poor. The concentration of the cellulose fiber raw material dispersion to be subjected to the defibrating treatment is preferably adjusted by appropriately adding water.

  As the dispersion medium, an organic solvent, water, or a mixed solution of an organic solvent and water can be used. Examples of organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, n-butanol, ethylene glycol and ethylene glycol mono-t-butyl ether, ketones such as acetone and methyl ethyl ketone, and other water-soluble organic compounds. One kind or two or more kinds of solvents can be used. The dispersion medium is preferably a mixed liquid of an organic solvent and water or water, and particularly preferably water.

  There are no particular restrictions on the method of defibrating the cellulose fiber raw material, but for example, ceramic beads having a diameter of about 1 mm are placed in the cellulose fiber raw material dispersion, and vibration is applied using a paint shaker or bead mill. Cellulosic fiber raw material is defibrated, blended with a blender-type disperser or a high-speed rotating slit, and a method of defibration by applying shear force through the cellulose fiber raw material dispersion (high-speed rotating homogenizer method) A method of using a counter impact type disperser (Masuko Sangyo) such as “massomizer X”, a method of generating a shearing force between cellulose fibers by depressurization to high pressure (high pressure homogenizer method), Can be mentioned. In particular, the high-speed rotating homogenizer and the high-pressure homogenizer treatment improve the efficiency of defibration.

  Note that, after the above-described processing, further miniaturization processing combined with ultrasonic processing may be performed.

  In addition, after performing the defibrating treatment, it is preferable to separate and remove the defibrated cellulose fibers in the fine cellulose fiber dispersion using centrifugation. By separating and removing cellulose fibers with poor defibration in the fine cellulose fiber dispersion by centrifugation, a supernatant of a more uniform and fine fine cellulose fiber dispersion can be obtained. The conditions for centrifugation are not particularly limited because they depend on the defibrating treatment used, but it is preferable to apply a centrifugal force of, for example, 3000 G or more, preferably 10,000 G or more. Further, the centrifugation time is, for example, 1 minute or longer, preferably 5 minutes or longer. If the centrifugal force is too small or the time is too short, separation / removal of poorly defibrated cellulose fibers becomes insufficient, which is not preferable.

Further, when the centrifugal separation is performed, it is not preferable that the fine cellulose fiber dispersion has a high viscosity because the separation efficiency is lowered. For this reason, as the viscosity of the fine cellulose fiber dispersion, the viscosity at a shear rate of 10 s ⁻¹ measured at 25 ° C. is 500 mPa · s or less, preferably 100 mPa · s or less.

[Olefin resin]
Hereinafter, the olefin resin which is the main resin of the cellulose fiber-containing resin composition of the present invention and a molded article using the same will be described specifically and in detail for each item.

[I] Olefin Resin As the olefin resin used in the cellulose fiber-containing resin composition of the present invention, an ethylene homopolymer, a propylene homopolymer, an α-olefin homopolymer having 4 to 20 carbon atoms, ethylene and carbon There are copolymers of two or more types of monomers selected from several to 20 α-olefins, low-density polyethylene resins by high-pressure radical polymerization, and propylene-based copolymers.

The monomer used for the polymerization of the olefin resin of the present invention is selected from ethylene and / or an α-olefin having 3 to 20 carbon atoms, and more preferably ethylene and / or an α-olefin having 3 to 12 carbon atoms. Specific examples include ethylene, propylene, butene-1, pentene-1, hexene-1, 4-methyl-1-pentene, octene-1, dodecene-1. As described above, the olefin resin may be a homopolymer of a monomer selected from ethylene or an α-olefin having 3 to 20 carbon atoms, or may be a copolymer of two or more types of monomers.

  The production method of the olefin-based resin is not particularly limited. For example, a method using a Ziegler-type, Phillips-type or metallocene-type catalyst and the like, a high-medium-low pressure method and other known polymerization methods, a tubular method, an autoclave method, etc. And a method of polymerizing by a known high-pressure radical polymerization method.

  Examples of the olefin resin using a metallocene catalyst include, for example, JP-A-8-325333, JP-A-9-031263, JP-A-9-087440, JP2001-525457, JP2004-53629. No., JP-A-2005-120385, JP-A-58-19309, JP-A-60-35005, JP-A-60-35006, JP-A-60-35007, JP-A-60-35007 60-35008, JP-A-60-35209, JP-A-61-130314, European Patent Application Publication No. 420,436, US Patent No. 5,055,438, International Publication Polymerization can be achieved by using a metallocene catalyst or various polymerization methods described in the specification of publication No. W091 / 04257.

[II] Olefin Resin Containing Polar Group In the olefin resin of the present invention, for example, a monomer selected from ethylene and an α-olefin having 3 to 20 carbon atoms and a vinyl monomer containing a polar group are copolymerized. The olefin copolymer obtained by doing this, the copolymer in which the vinyl group of the olefin resin containing a vinyl group is chemically modified to introduce a polar group into the olefin resin, or in the molecular chain by graft modification Also included are olefin copolymers containing polar groups (polar group-containing olefin resins) such as graft-modified olefin resins in which polar groups have been introduced. Use of an olefin resin containing a polar group, particularly an olefin resin containing a carboxylic acid group or an acid anhydride group as the polar group, is preferred because the dispersibility of the cellulose fibers is improved. This is presumably due to the interaction between this polar group and the hydroxyl group in the cellulose fiber.
The olefin-based resin containing the polar group is preferably contained in an amount of 5% by weight or more, more preferably 20% by weight or more, 50% by weight or more, and 80% by weight or more in the total resin component. As other resin components, other resins can be used as long as they do not deviate from the purpose of the present invention.

  A polar group used for polymerization of an olefin copolymer containing a polar group obtained by copolymerizing a monomer selected from ethylene and an α-olefin having 3 to 20 carbon atoms and a vinyl monomer containing a polar group Although the kind of vinyl monomer containing is not particularly limited, for example, vinyl esters such as vinyl propionate, vinyl acetate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl stearate, vinyl trifluoroacetate, (meth) acrylic Α, β-unsaturated carboxylic acid esters such as methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylic acid, maleic acid, fumaric acid and maleic anhydride Examples thereof include ethylenically unsaturated carboxylic acids such as acids or anhydrides thereof. Here, “(meth) acryl” is a general term for “acryl” and “methacryl”, and the same applies to “(meth) acrylate”.

  The manufacturing method of these polar group containing olefin copolymers is not specifically limited, A well-known method can be used. For example, polymerization by a high-pressure radical polymerization process (for example, the method described in Japanese Patent No. 2792982 and Japanese Patent Application Laid-Open No. 3-229713), copolymerization is carried out by masking the polar group of the polar group-containing monomer with organoaluminum or the like. After removing the mask (for example, the method described in Japanese Patent Nos. 4672214 and 36060385), a polar group-containing olefin copolymer in the presence of a catalyst in which a specific ligand is coordinated to a transition metal (For example, methods described in JP 2010-202647 A, JP 2010-150532 A, JP 2010-150246 A, and JP 2010-260913 A).

  The manufacturing method of the olefin resin in which the polar group is introduced into the olefin resin by chemically modifying the vinyl group of the olefin resin containing the vinyl group is not particularly limited, and a known method can be used. For example, in Japanese Patent Application Laid-Open No. 2006-131707, an olefinic resin is allowed to act on an olefinic resin having a vinyl group at the molecular chain end by allowing hydrogen, water or alcohol, and carbon monoxide to act in the presence of a catalyst. A method for introducing a carbonyl group into the molecular chain of a resin is described.

  The polar group-containing olefin resin used in the present invention may be a graft-modified olefin resin in which a polar group is introduced into a molecular chain by graft modification. Examples of the method of graft-modifying the polar group-containing monomer include a melting method in which an olefin resin is graft-modified in an extruder in the presence of a radical generator, or a solution method in which a reaction is performed in a solution.

  Examples of the radical generator include organic peroxides, dihydroaromatic compounds, dicumyl compounds and the like. Examples of the organic peroxide include hydroperoxide, dicumyl peroxide, t-butylcumyl peroxide, dialkyl (allyl) peroxide, diisopropylbenzene hydroperoxide, dipropionyl peroxide, dioctanoyl peroxide, and benzoyl. Peroxide, peroxysuccinic acid, peroxyketal, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane , T-butyloxyacetate, t-butylperoxyisobutyrate and the like. Examples of the dihydroaromatic compound include dihydroquinoline or a derivative thereof, dihydrofuran, 1,2-dihydrobenzene, 1,2-dihydronaphthalene, 9,10-dihydrophenanthrene and the like. Examples of the dicumyl compound include 2,3-dimethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-di (p-methylphenyl) butane, 2,3-diethyl-2,3-di (p-bromophenyl) butane and the like can be mentioned.

  The polar group-containing monomer subjected to graft modification is not particularly limited. For example, a carboxylic acid group or acid anhydride group-containing monomer (a), an ester group-containing monomer (b), a hydroxyl group-containing monomer (c), an amino group Examples thereof include a monomer containing monomer (d), a monomer containing silane group (e) and a monomer containing glycidyl group (f).

Examples of the carboxylic acid group or acid anhydride group-containing monomer (a) include α, β-unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid and itaconic acid, or anhydrides thereof, acrylic acid, methacrylic acid, Examples thereof include unsaturated monocarboxylic acids such as furan acid, crotonic acid, vinyl acetate and pentenoic acid.
Examples of the ester group-containing monomer (b) include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and butyl methacrylate.
Examples of the hydroxyl group-containing monomer (c) include hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.
Examples of the amino group-containing monomer (d) include aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, cyclohexylaminoethyl (meth) acrylate, and the like.
Examples of the silane group-containing monomer (e) include unsaturated silane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetylsilane, and vinyltrichlorosilane.
Examples of the glycidyl group-containing monomer (f) include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, 2-methylallyl glycidyl ether, and styrene-p-glycidyl ether.

  In consideration of the dispersibility of the cellulose fiber in the olefin resin, the carboxylic acid group or acid anhydride group-containing monomer (a) is more preferable. As described above, this is presumably due to the interaction between the polar group of the monomer and the hydroxyl group in the cellulose fiber, thereby increasing the dispersibility.

[III] Mixing of Cellulose Fiber and Olefin Resin and Production of Pellet In the cellulose fiber-containing resin composition of the present invention, the mixing ratio of cellulose fiber and olefin resin depends on the intended physical properties and the physical properties of the olefin resin itself. Usually, the cellulose fiber content in the cellulose fiber-containing resin composition of the present invention is 0.1 to 500 weight in terms of dry weight of cellulose fiber with respect to 100 parts by weight of the olefin resin. Parts, more preferably 1 to 400 parts by weight, still more preferably 5 to 300 parts by weight. When the cellulose fiber content in the cellulose fiber-containing resin composition is less than the above lower limit, the reinforcing effect of the olefin resin by the cellulose fiber is hardly seen, and when it is more than the above upper limit, the cellulose fiber resin composition is melted. In some cases, the viscosity becomes extremely high, and the molding process becomes difficult.
In the cellulose fiber-containing resin composition of the present invention, one type of olefinic resin may be used alone, or two or more different types such as resin types and introduced polar groups may be used in combination. Also good. Further, a resin other than the olefin resin may be further blended.

  Moreover, about cellulose fiber, only 1 type may be used and what has a different functional group etc. may be used in combination of 2 or more types.

  In addition, the dry weight conversion value of a cellulose fiber measures the moisture content (weight%) which a cellulose fiber contains beforehand, and calculates the moisture-containing cellulose fiber with which it uses for manufacture of a cellulose fiber containing resin composition by the following Formula. It is the conversion value calculated by the thing.

  The mixing method of the cellulose fiber and the olefin resin is not particularly limited, and a known method can be applied. However, considering the simplicity of the process and the production efficiency, a method of mechanically kneading using an extruder or a kneader Is preferred.

  Specifically, the cellulose fiber and the olefin resin are dry blended in advance, and the blended product is melt-kneaded by an extruder or the like, the olefin resin is melt-kneaded in advance, and the cellulose fiber is later The method of throwing in is mentioned.

  In the dry blending of the cellulose fiber and the olefin resin, a tumbler mixer, a Henschel mixer, a super mixer, or the like can be used. Moreover, you may mix the below-mentioned various additives simultaneously with mixing of a cellulose fiber and an olefin resin.

  Examples of the melt-kneading apparatus include a single screw extruder, a twin screw extruder, a kneader, and a Banbury mixer. Moreover, when a cellulose fiber or olefin resin contains volatile components, such as a water | moisture content, it is preferable to attach a devolatilization apparatus to a melt-kneading apparatus.

  Although the temperature at the time of melt-kneading is suitably set according to the melting temperature of the main material resin, for example, it is in the range of 90 to 300 ° C.

  The cellulose fiber-containing resin composition of the present invention uniformly mixed by a melt kneader can be cut into granular pellets having a diameter of 1 to 10 mm by various pelletizers and used for various molding methods. The pelletizer is not particularly limited, and a known method can be applied. Specifically, from an underwater pelletizer that extrudes and cuts directly from the kneader's die into water, and from a die that is extruded as a rod-like strand, cooled by water or air cooling to a non-attaching temperature, and then cut by a rotating blade. Any hot cut pelletizer that extrudes and cuts immediately in the air can be suitably used. Depending on the type of pelletizer, the pellet takes various shapes such as a columnar shape, a lens shape, and a spherical shape, and any of them can be suitably used. The particle size of the pellet is preferably 1 to 10 mm. A pellet of less than 1 mm is not preferable because it is difficult to cut with a pelletizer, and the bulk density becomes small, and a large space is required for storage and transportation of the product. Of the various melt molding methods exemplified in [IV] molding method in the post-process, in the method using a screw extruder, pellets having a diameter larger than the groove depth of the screw cannot be extruded. It is practically difficult to use.

[IV] Molding Method As a molding method for the molded body comprising the cellulose fiber-containing resin composition of the present invention, various thermoforming methods generally used for thermoplastic resin molding can be suitably used. Specifically, press molding, T-die cast sheet molding, calendar molding, vacuum molding, vacuum-pressure air molding, rotational molding, blow molding, air-cooled inflation film molding, air-cooled two-stage cooling inflation film molding, water-cooled inflation film molding, T-die cast Examples include film forming, extrusion laminating, foaming, injection molding, and other extrusion mold materials and extrusion molding used for processing fibers, monofilaments, multifilaments, nonwoven fabrics, pipes, and the like.

  The cellulose fiber-containing resin composition of the present invention may be used alone for various moldings, but polyolefin resin such as polyethylene and polypropylene, polyamide resin, polyester resin, saponified ethylene / vinyl acetate copolymer resin (EVOH) It may be used by being laminated with a thermoplastic resin layer such as aluminum or a metal material such as aluminum or steel. As a method of laminating, various known methods can be used. For example, ordinary press molding, coextrusion inflation molding, coextrusion cast molding, coextrusion blow molding, two-color injection molding, extrusion laminating, sand laminating. Examples include processing, dry laminating, and heat sealing.

[V] Additives In the cellulose fiber-containing resin composition of the present invention, an antioxidant, an ultraviolet absorber, a lubricant, an antistatic agent, a colorant, a pigment, a crosslinking agent, and foaming are used without departing from the gist of the present invention. You may mix | blend additives, such as an agent, a nucleating agent, a flame retardant, and a filler.

[Usage]
The cellulose fiber-containing resin composition of the present invention has excellent transparency and rigidity, and further has a low linear expansion coefficient. Therefore, applications that require such performance, such as agricultural films such as agricultural poly and agricultural PO, various packaging films such as standard bags, plastic bags, compost bags, and transparent blowers that allow visual inspection of contents. It can be used for bottles, squeeze bottles, medical, food, beverages, injection-molded products for office equipment, solar cell sealing materials, etc., and has high utility value for various industrial fields.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Below, the measuring method of the various physical properties of the resin which does not contain a cellulose fiber containing resin composition or a cellulose fiber is as follows.

[Measurement of physical properties]
<Transparency>
Haze was measured according to JIS-K7136-2000, and transparency was evaluated based on the measured value. In order to remove the influence of the sheet surface on the measurement value, the Haze in a state where the press sheet was immersed in a quartz cell filled with special grade liquid paraffin manufactured by Kanto Chemical Co., that is, the internal Haze was measured. The smaller the value of the internal haze, the better the transparency.
The method for preparing the test piece and the method for processing the measurement data are as follows.
The cellulose fiber-containing resin compositions of Examples and Comparative Examples or resin pellets containing no cellulose fiber were placed in a hot press mold having a thickness of 0.1 mm, and preheated for 3 minutes in a hot press machine having a surface temperature of 150 ° C. Thereafter, the residual gas in the molten resin was degassed by repeating pressurization and decompression, and further pressurized at 4.9 MPa and held for 3 minutes. Then, it transferred to the press machine with a surface temperature of 25 degreeC, it cooled by hold | maintaining for 3 minutes with the pressure of 4.9 Mpa, and produced the press sheet about 0.1 mm thick. The thickness of each press sheet was measured with a micrometer, and after measuring the internal haze, it was converted into a thickness of 0.1 mm according to the following formula to obtain measurement data.

<Tensile yield strength / tensile modulus>
(Manufacturing method of tensile test sample)
The cellulosic fiber-containing resin composition of each example and each comparative example or resin pellets containing no cellulose fiber was placed in a hot press mold having dimensions of 50 mm × 60 mm and a thickness of 1 mm, and a hot press machine having a surface temperature of 160 ° C. After preheating for 5 minutes, residual gas in the molten resin was degassed by repeating pressurization and decompression, and further pressurized at 4.9 MPa and held for 5 minutes. Thereafter, the sheet was gradually cooled at a rate of 10 ° C./min with a pressure of 4.9 MPa, and the press sheet was taken out of the mold when the temperature dropped to near room temperature. The obtained press sheet was kept for 48 hours or more in an environment of temperature 23 ± 2 ° C. and humidity 50 ± 5 ° C. to adjust the state. A test piece having the shape of the test piece 5B described in JIS K 7162 was punched out of the press sheet after the state adjustment to obtain a tensile test sample.
(Tensile test conditions)
With reference to JIS K 7161, the tensile yield strength and the tensile elastic modulus were measured. The specimen shape is the above JIS
Test piece 5B type described in K7162, Tensilon (model: RTG-1250) manufactured by A & D Co., Ltd. was used for the tensile test. The tensile speed when measuring the tensile yield strength was 1.0 mm / min, and the tensile speed when measuring the tensile modulus was 0.2 mm / min.

<Linear expansion coefficient>
(Production method of linear expansion coefficient sample)
A press sheet was prepared in the same manner as in the method for producing a tensile test sample except that a 0.2 mm thick press mold was used. The obtained press sheet was conditioned for 48 hours or more in an environment of temperature 23 ± 2 ° C. and humidity 50 ± 5 ° C., and then annealed in an oven at 80 ° C. for 10 hours. From this, a sample with a width of 3 mm and a length of 30 mm was used as a linear expansion coefficient sample.
(Linear expansion coefficient measurement conditions)
10 mm / min. From room temperature to −40 ° C. in a tensile mode using a TMA6100 manufactured by SII in a tension mode, 20 mm between chucks, 4 g load, nitrogen atmosphere. At 5 ° C./min. The linear expansion coefficient was determined from the measured value when the temperature was raised to 80 ° C.

[Production Example 1: Production of chemically modified cellulose fiber (A-1)]
Hardwood bleached kraft pulp (LBKP, manufactured by Oji Paper Co., Ltd .: moisture content 30 wt%, freeness 600 mLcsf) as a cellulose fiber raw material was weighed 100 parts by weight in solid content, stirred in 50 volumes of acetone and filtered. Further, 50 times the amount of acetone was poured to replace the water in the cellulose fiber raw material with acetone. 2400 parts by weight of dimethylformamide and 440 parts by weight of pyridine were mixed, and an acetone-substituted cellulose fiber raw material was added thereto. After the inside of the system was purged with nitrogen, 150 parts by weight of octanoyl chloride was added while stirring the system, and the mixture was stirred and reacted at 110 ° C. for 7 hours. After cooling, the reaction product was washed with ethanol and subsequently with water and filtered to obtain hydrous octanoylated cellulose fibers (cake). The chemical modification rate (octanoyl group content) of this octanoylated cellulose fiber (chemically modified cellulose fiber (A-1)) was 29 mol%.

[Production Example 2: Production of chemically modified cellulose fiber (A-2)]
A hydrous lauroylated cellulose fiber (cake) was obtained in the same manner as in Production Example 1 except that octanoyl chloride was changed to 200 parts by weight of lauroyl chloride and washing after the reaction was performed with acetone and water. The chemical modification rate (content of lauroyl group) of the lauroylated cellulose fiber (chemically modified cellulose fiber (A-2)) was 30 mol%.

[Production Example 3: Production of chemically modified cellulose fiber (A-3)]
A hydrous stearoylated cellulose fiber (cake) was obtained in the same manner as in Production Example 1 except that octanoyl chloride was changed to 280 parts by weight of stearoyl chloride and washing after the reaction was performed with toluene, acetone and water. The chemical modification rate (stearoyl group content) of this stearoylated cellulose fiber (chemically modified cellulose fiber (A-3)) was 6 mol%.

[Production Example 4: Production of chemically modified cellulose fiber (A-4)]
Wood flour (US pine) was degreased with a 2% by weight aqueous solution of sodium carbonate at 90 ° C. for 4 hours and washed with demineralized water to obtain a degreased wood flour. The defatted wood flour was treated in a peracetic acid aqueous solution at 90 ° C. for 1 hour, then washed with demineralized water to obtain a delignified wood flour. The obtained delignified wood powder was immersed in a 5% by weight aqueous solution of potassium hydroxide for 16 hours, washed with demineralized water, and a cellulose fiber raw material treated with dehemicellulose was obtained.
The operation of stirring and filtering 100 parts by weight of this cellulose fiber raw material in 16 parts by weight of acetic acid was repeated twice to replace the water in the cellulose fiber raw material with acetic acid. This cellulose fiber raw material, 1050 parts by weight of acetic acid and 1085 parts by weight of acetic anhydride were mixed, and the system was purged with nitrogen, followed by reaction at 115 ° C. for 4 hours. After cooling, it was washed with methanol and then with water to obtain hydrous acetylated cellulose fibers (cake). The chemical modification rate (acetyl group content) of this acetylated cellulose fiber (chemically modified cellulose fiber (A-4)) was 23 mol%.

[Production Example 5: Production of chemically modified cellulose fiber (A-5)]
Hardwood bleached kraft pulp (LBKP, manufactured by Oji Paper Co., Ltd .: moisture 22%, freeness 600 mLcsf) as a cellulose fiber raw material was weighed 100 parts by weight in solid content, and 3900 parts by weight of butyric anhydride was added. The system was purged with nitrogen while stirring, and then reacted at 60 ° C. for 1 hour and then at 115 ° C. for 5 hours. After cooling, it was washed with methanol and then with water to obtain hydrous butyryl cellulose fibers (cake). The chemical modification rate (butyryl group content) of this butyryl cellulose fiber (chemically modified cellulose fiber (A-5)) was 7 mol%.

[Production Example 6: Method for producing cellulose fiber (A-6)]
Wood flour (US pine) was degreased with a 2% by weight aqueous solution of sodium carbonate at 80 ° C. for 6 hours and washed with demineralized water to obtain a degreased wood flour. The defatted wood powder was treated with sodium chlorite under acetic acid at 80 ° C. for 5.5 hours, and then washed with demineralized water to obtain a delignified wood powder. The obtained delignified wood powder was immersed in a 5% by weight aqueous solution of potassium hydroxide for 16 hours, washed with demineralized water, and a cellulose fiber raw material treated with dehemicellulose was obtained.
Using cellulose fiber raw material slurry 6.2L adjusted to 3.6% by weight with demineralized water, using a high-speed rotating homogenizer ("CLEAMIX 2.2S" screen S1.0-24, rotor R1 manufactured by M Technique Co., Ltd.) A dispersion of fine (unmodified) cellulose fibers was obtained by continuous treatment at 20000 rpm for 6 hours.

  Table 1 summarizes the chemical modification rates of the chemically modified cellulose fibers and unmodified cellulose fibers obtained in Production Examples 1 to 6, and the cellulose fiber concentration of the dispersion of cellulose fibers.

[Production Example 7: Production of modified polyethylene]
100 parts by weight of linear low density polyethylene (manufactured by Nippon Polyethylene, trade name: F30HG), 0.6 parts by weight of maleic anhydride (trade name: SY-A, manufactured by NOF Corporation), 2,5-dimethyl-2, Add 0.02 part by weight of 5-bis (t-butylperoxy) hexane (trade name: Perhexa 25B, manufactured by NOF Corporation), mix well with a Henschel mixer, and use a φ50 mm single screw extruder at a set temperature of 290. Graft modification was performed by melt-kneading at 0 ° C. By pelletizing the resin extruded in a strand shape, pellets of modified polyethylene were produced.

[Example 1: Production of cellulose fiber-containing resin composition (B-1)]
The cake of chemically modified cellulose fiber (A-1) obtained in Production Example 1 with respect to 100 parts by weight of linear low density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., trade name: F30HG, indicated as “LLDPE” in the table) (Water-containing octanoylated cellulose fiber) 58 parts by weight were added, dry blended, and charged into a small twin-screw kneader (Model: MC15, manufactured by DSM Xplore). At this time, the barrel temperature was 150 ° C. and the screw rotation speed was 150 rpm. Under these conditions, melt kneading was performed for 5 minutes. Since the melt-kneading temperature was higher than the boiling point of water, most of the water contained in the cellulose fiber dispersion evaporated during the kneading. The resin temperature during kneading was 140 ° C. After 5 minutes, the rod-like cellulose fiber-containing resin composition (B-1) was extruded from the resin discharge port, placed on a stainless steel tray, and cooled and solidified at room temperature. The cooled cellulose fiber-containing resin composition (B-1) was cut into pellets to produce pellets of the cellulose fiber-containing resin composition (B-1).
Table 2 summarizes the measurement results of the amount of chemically modified cellulose fibers, chemical modification groups, and physical properties contained in the cellulose fiber-containing resin composition (B-1).

[Example 2: Production of cellulose fiber-containing resin composition (B-2)]
The amount of the chemically modified cellulose fiber (A-1) cake is changed to the chemically modified cellulose fiber (A-2) cake (hydrous lauroylated cellulose fiber) obtained in Production Example 2, and the blending amount is shown in Table 2. A cellulose fiber-containing resin composition (B-2) was produced by the same method as in Example 1 except that the measurement results of the physical properties were summarized in Table 2.

[Example 3: Production of resin composition containing cellulose fiber (B-3)]
The amount of the chemically modified cellulose fiber (A-1) cake is changed to the chemically modified cellulose fiber (A-3) cake (hydrous stearoylated cellulose fiber) obtained in Production Example 3, and the amount shown in Table 2 A cellulose fiber-containing resin composition (B-3) was produced in the same manner as in Example 1 except that the measurement results of the physical properties were summarized in Table 2.

[Example 4: Production of cellulose fiber-containing resin composition (B-4)]
A cellulose fiber-containing resin composition (by a method similar to that of Example 1) except that the linear low density polyethylene was changed to a modified polyethylene graft-modified by the method of Production Example 7 (indicated in the table as “modified LLDPE”). B-4) was produced, and the measurement results of each physical property are summarized in Table 2. In addition, the number average fiber diameter of the cellulose fiber in this composition was 420 nm.

[Example 5: Production of cellulose fiber-containing resin composition (B-5)]
A cellulose fiber-containing resin composition (B-) was obtained by the same method as in Example 2 except that the linear low density polyethylene was changed to a modified polyethylene (denoted as modified LLDPE in the table) graft-modified by the method of Production Example 7. 5) was manufactured, and the measurement results of each physical property are summarized in Table 2. In addition, the number average fiber diameter of the cellulose fiber in this composition was 390 nm.

[Example 6: Production of cellulose fiber-containing resin composition (B-6)]
A cellulose fiber-containing resin composition (by a method similar to that of Example 3) except that the linear low density polyethylene was changed to a modified polyethylene graft-modified by the method of Production Example 7 (denoted as “modified LLDPE” in the table). B-6) was produced, and the measurement results of each physical property are summarized in Table 2. In addition, the number average fiber diameter of the cellulose fiber in this composition was 270 nm.

[Example 7: Production of cellulose fiber-containing resin composition (B-7)]
A cellulose fiber-containing resin composition (B-) was prepared in the same manner as in Example 6 except that the amount of the chemically modified cellulose fiber (A-3) cake (hydrous stearoylated cellulose fiber) was changed to the amount shown in Table 2. 7) was prepared, and the measurement results of each physical property are summarized in Table 2. In addition, the number average fiber diameter of the cellulose fiber in this composition was 800 nm.

[Example 8: Production of cellulose fiber-containing resin composition (B-8)]
A cellulose fiber-containing resin composition (B-) was prepared in the same manner as in Example 6 except that the amount of the chemically modified cellulose fiber (A-3) cake (hydrous stearoylated cellulose fiber) was changed to the amount shown in Table 2. 8) was prepared, and the measurement results of each physical property are summarized in Table 2.

[Comparative Example 1: Linear low density polyethylene]
Various physical properties of a linear low density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., trade name: F30HG, expressed as “LLDPE” in the table) were measured, and the results are summarized in Table 3.

[Comparative Example 2: Modified polyethylene]
Various physical properties of a single modified polyethylene (denoted as “modified LLDPE” in the table) obtained by graft-modifying linear low density polyethylene by the method of Production Example 7 were measured, and the results are summarized in Table 3.

[Comparative Example 3: Production of Cellulose Fiber-Containing Resin Composition (B-9)]
The amount of the chemically modified cellulose fiber (A-1) cake is changed to the chemically modified cellulose fiber (A-4) cake (hydrous acetylated cellulose fiber) obtained in Production Example 4, and the amount shown in Table 3 A cellulose fiber-containing resin composition (B-9) was produced by the same method as in Example 1 except that the measurement results of the physical properties were summarized in Table 3.

[Comparative Example 4: Production of cellulose fiber-containing resin composition (B-10)]
The amount of the chemically modified cellulose fiber (A-1) cake is changed to the chemically modified cellulose fiber (A-5) cake (hydrous butyryl cellulose fiber) obtained in Production Example 5 and the blending amount is shown in Table 3. A cellulose fiber-containing resin composition (B-10) was produced by the same method as in Example 1 except that the measurement results of the physical properties were summarized in Table 3.

[Comparative Example 5: Production of cellulose fiber-containing resin composition (B-11)]
A cellulose fiber-containing resin composition (by a method similar to Comparative Example 3) except that the linear low density polyethylene was changed to a modified polyethylene graft-modified by the method of Production Example 7 (denoted as “modified LLDPE” in the table). B-11) was produced, and the measurement results of each physical property are summarized in Table 3. The number average fiber diameter of the cellulose fibers in this composition was 1.5 μm.

[Comparative Example 6: Production of cellulose fiber-containing resin composition (B-12)]
The cellulose fiber-containing resin composition (by the same method as in Comparative Example 4) except that the linear low-density polyethylene was changed to a modified polyethylene graft-modified by the method of Production Example 7 (indicated in the table as “modified LLDPE”). B-12) was produced, and the measurement results of each physical property are summarized in Table 3. The number average fiber diameter of the cellulose fibers in this composition was 2.8 μm.

[Comparative Example 7: Production of cellulose fiber-containing resin composition (B-13)]
The cake of chemically modified cellulose fiber (A-1) was changed to the dispersion of cellulose fiber (A-6) obtained in Production Example 6, and the blending amount of this dispersion was changed to the amount shown in Table 3. Manufactured the cellulose fiber containing resin composition (B-13) by the method similar to Example 1, and summarized the measurement result of each physical property in Table 3.

[Comparative Example 8: Production of cellulose fiber-containing resin composition (B-14)]
A cellulose fiber-containing resin composition (by a method similar to that in Comparative Example 7) except that the linear low density polyethylene was changed to a modified polyethylene graft-modified by the method of Production Example 7 (denoted as “modified LLDPE” in the table). B-14) was produced, and the measurement results of each physical property are summarized in Table 3.

As is clear from the comparison between Examples 1 to 6 and Comparative Examples 1 to 8, the cellulose fiber-containing resin composition of the present invention of Examples 1 to 6 was obtained by using cellulose fibers into which specific functional groups were introduced. While increasing the tensile yield strength and tensile modulus, the effect on transparency is small.
Comparative Examples 1 and 2 are LLDPE simple substance and modified LLDPE simple substance, respectively. Comparative Examples 3 to 8 in which a cellulose fiber into which a functional group having 3 or less carbon atoms in an aliphatic hydrocarbon chain is introduced or a cellulose fiber that has not been chemically modified are blended with this main material resin has some tensile yield strength. Although the tensile modulus is improved, the transparency is remarkably lowered. On the other hand, in Examples 1-6, the improvement effect of tensile yield strength and a tensile elasticity modulus is large compared with Comparative Examples 3-8, On the other hand, the fall of transparency is small.
Examples 6 to 8 are resin compositions in which the addition amount of the chemically modified cellulose fiber (A-3) contained in the modified LLDPE is different. From these results, the chemically modified cellulose fiber (A-3) It can be seen that as the content increases, mechanical properties such as tensile yield strength and tensile elastic modulus improve, but there is little difference in transparency.
In view of the above, if it is a cellulose fiber-containing resin composition in which a cellulose fiber into which a specific functional group is introduced is contained in an olefin resin, the mechanical properties are remarkably reduced while suppressing a decrease in transparency due to the blending of the cellulose fibers. It can be seen that it can be raised. This has shown that the cellulose fiber containing resin composition of this invention has outstanding performance.

Claims (7)

A fiber-containing resin composition comprising cellulose fibers and an olefin resin,
The cellulose constituting the cellulose fiber has a functional group having a linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms, and a cellulose fiber-containing resin composition.   The cellulose fiber-containing resin composition according to claim 1, wherein the olefin resin contains a polar group-containing olefin resin.   The cellulose fiber-containing resin composition according to claim 2, wherein the polar group-containing olefin resin is a polar group-containing olefin resin having a carboxylic acid group or an acid anhydride group.   The cellulose fiber according to any one of claims 1 to 3, wherein the cellulose fiber is contained in an amount of 0.1 to 500 parts by weight in terms of dry weight with respect to 100 parts by weight of the olefin resin. Containing resin composition.   The cellulose fiber-containing resin composition according to any one of claims 1 to 4, wherein the average fiber diameter of the cellulose fibers is 2 nm to 1500 nm.   The content of the functional group having the linear or branched aliphatic hydrocarbon chain having 5 or more carbon atoms in the cellulose fiber is 1.6 mol% to 66.0 mol%, 6. Cellulose fiber-containing resin composition described in 1.   The pellet containing the cellulose fiber containing resin composition as described in any one of Claims 1 thru | or 6.