JP5163138B2 - Cellulose / polyolefin composite materials - Google Patents

Description

  The present invention relates to (A) a cellulose nonwoven fabric, (B) a modified polyolefin having a functional group, and (C) a cellulose / polyolefin composite material containing polyolefin, and a method for producing the cellulose / polyolefin composite material.

  Polyolefin is inexpensive and has excellent mechanical properties, heat resistance, chemical resistance, water resistance, and the like, and is therefore used in a wide range of fields. Among these, polypropylene is used in automobiles for exterior parts such as bumpers, rocker moldings, side moldings, and over fenders, and interior parts such as instrument panels, glove boxes, door liners, pillars, and the like. On the other hand, since polypropylene has high crystallinity, it is also known that the dimensional change (linear expansion coefficient) with respect to temperature is very large. And due to this property, in parts using polypropylene materials, especially large parts such as bumpers and instrument panels, gaps are created at the joints of parts, and the ease of installation when assembling the parts is reduced. The problem was occurring.

  On the other hand, composite materials using fine cellulose fibers have been studied extensively. It is known that cellulose has a low linear expansion coefficient, a high elastic modulus, and a high strength when combined with a resin because of its extended chain crystal.

For example, Patent Document 1 discloses a method in which a cellulose non-woven fabric is impregnated with a thermoplastic resin and then dried or defoamed and then cooled to be combined with the resin.
JP 2006-316253 A

However, when a cellulose nonwoven fabric and a polyolefin are compounded by the method described in Patent Document 1, it is necessary to dissolve a polyolefin in a solvent or impregnate it into a cellulose nonwoven fabric as a melt, which requires a large amount of heat energy. Therefore, even if heated to a high temperature and dissolved in a solvent or made into a melt, they are usually not substantially impregnated into cellulose fibers. Further, when a modified polyolefin is used as the polyolefin, it can be dissolved in a solvent, but the modified polyolefin is not substantially impregnated into the cellulose fiber.
For these reasons, it has been desired to develop a cellulose / polyolefin composite material that can be easily produced industrially.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a cellulose / polyolefin composite material that is excellent in both physical property balance and linear expansion characteristics and can be easily manufactured.

The cellulose / polyolefin composite material of the present invention (Claim 1) is (A) a cellulose non-woven fabric containing no cellulose fiber having a fiber diameter of 1500 nm or more, (B) a modified polyolefin having a functional group, and (C) a polyolefin. In which the content of the cellulose nonwoven fabric is 10 to 80% by weight, and (B) the modified polyolefin having a functional group is a maleic anhydride-modified polyolefin and / or cation. A polyolefin containing a functional group .

According to the present invention, (B) the modified polyolefin having a functional group is allowed to function as an adhesive between (A) a cellulose nonwoven fabric and (C) a polyolefin, and is excellent in adhesion and integrity between the cellulose nonwoven fabric and the resin. By making it a composite material, (C) improving the physical properties of polyolefin, for example, improving rigidity, improving gas barrier properties, improving flame retardancy, reducing molding shrinkage, reducing thermal expansion, A cellulose / polyolefin composite material having an excellent balance of physical properties can be provided.
Moreover, the cellulose / polyolefin composite material of the present invention can be easily produced by, for example, immersing or applying (B) a modified polyolefin having a functional group to (A) a cellulose nonwoven fabric and then bonding (C) the polyolefin. can do.

  Embodiments of the present invention will be specifically described below, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

{Cellulose / polyolefin-based composite material}
The cellulose / polyolefin composite material of the present invention contains a cellulose nonwoven fabric, (B) a polyolefin having a functional group, and (C) a polyolefin.

[(A) Cellulose nonwoven fabric]
The cellulose nonwoven fabric according to the present invention is a nonwoven fabric mainly composed of cellulose, and is an aggregate of cellulose fibers. The cellulose nonwoven fabric can be obtained by a method of forming a cellulose dispersion by papermaking or coating, or a method of drying a gel film.

<Fiber diameter>
It is preferable that the fiber diameter of the cellulose fiber which comprises a cellulose nonwoven fabric is thin. Specifically, it is preferable not to include fibers having a fiber diameter of 1500 nm or more, more preferably not including fibers having a fiber diameter of 1000 nm or more, particularly preferably including fibers having a fiber diameter of 500 nm or more. Preferably it is not. Nonwoven fabrics that do not contain fibers having a fiber diameter of 1500 nm or more are preferred in that a low linear expansion coefficient can be obtained when they are combined with a resin.
In addition, the fiber diameter of a cellulose fiber can be confirmed by SEM observation.

<Raw material>
Examples of the raw material for the cellulose nonwoven fabric include woody materials such as conifers and broad-leaved trees, bacterial cellulose produced by bacteria, cotton such as cotton linter and cotton lint, seaweeds such as valonia and sturgeon, and scallops. These natural celluloses are preferable because of their high crystallinity and low linear expansion coefficient. 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 earth, and 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.

<Chemical modification>
The cellulose nonwoven fabric may be chemically modified. The chemical modification means that the hydroxyl group in cellulose is chemically modified by reacting with a chemical modifier.

(type)
As functional groups to be introduced into cellulose by chemical modification, acetyl group, acryloyl group, methacryloyl group, propionyl group, propioroyl group, butyryl group, 2-butyryl group, pentanoyl group, hexanoyl group, heptanoyl group, octanoyl group, nonanoyl group, Decanoyl group, undecanoyl group, dodecanoyl group, myristoyl group, palmitoyl group, stearoyl group, pivaloyl group, benzoyl group, naphthoyl group, nicotinoyl group, isonicotinoyl group, furoyl group, acyl group such as cinnamoyl group, 2-methacryloyloxyethylisocyanoyl Isocyanate group such as a group, methyl group, ethyl group, propyl group, 2-propyl group, butyl group, 2-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, noni Group, decyl group, undecyl group, dodecyl group, myristyl group, palmityl group, an alkyl group such as a stearyl group, an oxirane group, an oxetane group, a thiirane group, or the like thietane group. Among these, an acyl group having 2 to 12 carbon atoms such as an acetyl group, an acryloyl group, a methacryloyl group, a benzoyl group and a naphthoyl group, and an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group and a propyl group are preferable. .

(Modification method)
The modification method is not particularly limited, and there is a method of reacting cellulose with a chemical modifier as described below. 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.

  As a kind of chemical modifier, 1 type, or 2 or more types chosen from the group which consists of cyclic ethers, such as an acid, an acid anhydride, alcohol, a halogenating reagent, isocyanate, alkoxysilane, and an oxirane (epoxy), are mentioned.

  Examples of the acid include acetic acid, acrylic acid, methacrylic acid, propanoic acid, butanoic acid, 2-butanoic acid, and pentanoic acid.

  Examples of the acid anhydride include acetic anhydride, acrylic anhydride, methacrylic anhydride, propanoic anhydride, butanoic anhydride, 2-butanoic anhydride, and pentanoic anhydride.

  Examples of the alcohol include methanol, ethanol, propanol, and 2-propanol.

  Examples of the halogenating reagent include acetyl halide, acryloyl halide, methacryloyl halide, propanoyl halide, butanoyl halide, 2-butanoyl halide, pentanoyl halide, benzoyl halide, and naphthoyl halide.

  Examples of the isocyanate include methyl isocyanate, ethyl isocyanate, propyl isocyanate, and the like.

  Examples of the alkoxysilane include methoxysilane and ethoxysilane.

  Examples of cyclic ethers such as oxirane (epoxy) include ethyl oxirane and ethyl oxetane.

Among these, acetic anhydride, acrylic acid anhydride, methacrylic acid anhydride, benzoyl halide, and naphthoyl halide are particularly preferable.
These chemical modifiers may be used alone or in combination of two or more.

(Chemical modification rate)
The term “chemical modification rate” as used herein refers to the proportion of all hydroxyl groups in cellulose that have been chemically modified, and the chemical modification rate can be measured by the following titration method.

これを解いていくと、以下の通りである。

<Measuring method>
0.5 g of cellulose nonwoven fabric is precisely weighed, and 6 ml of methanol and 2 ml of distilled water are added thereto. This is stirred at 60-70 ° C. for 30 minutes, and then 10 ml of 0.05N aqueous sodium hydroxide solution is added. The mixture is stirred at 60 to 70 ° C. for 15 minutes and further stirred at room temperature for one day. Titrate with 0.02N aqueous hydrochloric acid using phenolphthalein.
Here, from the amount Z (ml) of the 0.02N hydrochloric acid aqueous solution required for the titration, the number of moles Q of the substituent introduced by chemical modification is obtained by the following formula.
Q (mol) = 0.05 (N) × 10 (ml) / 1000
−0.02 (N) × Z (ml) / 1000
The relationship between the number of moles Q of the substituent and the chemical modification rate X (mol%) is calculated by the following formula (cellulose = (C ₆ O ₅ H ₁₀ ) _n = (162.14) _n , repetition Number of hydroxyl groups per unit = 3, molecular weight of OH = 17). In the following, T is the molecular weight of the substituent.

Solving this, it is as follows.

  In this invention, it is preferable that the chemical modification rate of a cellulose nonwoven fabric is 65 mol% or less with respect to all the hydroxyl groups of a cellulose, and it is further more preferable that it is 50 mol% or less. If this chemical modification rate is too high, the cellulose structure is destroyed and the crystallinity is lowered, and therefore, there is a problem that the linear expansion coefficient of the obtained composite material becomes large, which is not preferable.

<Method for producing cellulose nonwoven fabric>
Although the manufacturing method of a cellulose nonwoven fabric is not specifically limited, For example, it can manufacture as follows.

  In the production of the nonwoven fabric, the cellulose raw material is refined or refined as necessary, and then the cellulose dispersion (usually an aqueous dispersion of cellulose) is formed by filtration or coating to form a gel film. The film is dried to form a non-woven fabric, but it is preferably washed or immersed in an organic solvent such as alcohol before the drying.

  The chemical modification may be performed after film formation on a nonwoven fabric, or may be performed on cellulose before film formation on the nonwoven fabric, but the former is preferable. In that case, the cellulose substituted with an organic solvent such as alcohol is formed into a non-woven fabric and then chemically modified. After the chemical modification is completed, it is preferable to wash thoroughly with water, and then replace the remaining water with an organic solvent such as alcohol and dry.

  The method for producing such a nonwoven fabric will be described in more detail.

(Manufacture of non-woven fabric)
For the production of the nonwoven fabric, refined cellulose fibers are used.
When bacterial cellulose is used as a cellulose raw material, cellulose fibers can be obtained by culturing bacteria that produce cellulose. By removing this product from the medium and removing it by washing it with water or treating it with alkali, for example, water-containing bacterial cellulose containing no bacteria can be obtained. Since bacteria produce fine cellulose, they can be used as they are without being refined.
After refining wood such as conifers and hardwoods, and cotton such as cotton linters and cotton lint, they are refined to obtain refined cellulose. Further, seaweeds such as valonia and squirrel and squirts of sea squirts are refined to obtain refined cellulose.

  As a disperser for refining cellulose, it is preferable to use a blender type disperser, a high-pressure homogenizer, an ultrahigh-pressure homogenizer, or the like. In particular, the ultra-high pressure homogenizer is effective in uniformly refining cellulose.

  It is preferable that the cellulose concentration of the cellulose dispersion at the time of refining is 0.05% by weight or more, preferably 0.1% by weight or more, and more preferably 0.3% by weight or more. If the cellulose concentration is too low, it takes too much time to filter and apply. The cellulose concentration is preferably 10% by weight or less, preferably 3% by weight or less, and more preferably 2% by weight or less. If the cellulose concentration is too high, the viscosity becomes too high or a uniform cellulose nonwoven fabric cannot be obtained.

  When a nonwoven fabric is obtained by filtration, the concentration of the cellulose dispersion is preferably 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more. If the concentration is too low, filtration takes an enormous amount of time, which is not preferable. The concentration of the cellulose dispersion is 1.5% by weight or less, preferably 1.2% by weight or less, more preferably 1.0% by weight or less. If the concentration is too high, a uniform nonwoven fabric cannot be obtained.

In addition, as a filter cloth at the time of filtration, it is important that fine cellulose does not pass through and the filtration rate is not too slow. Such a filter cloth is preferably a nonwoven fabric, a woven fabric, or a porous membrane made of an organic polymer. The organic polymer is preferably a non-cellulose organic polymer such as polyethylene terephthalate, polyethylene, polypropylene, polytetrafluoroethylene (PTFE) or the like.
Specifically, a porous film of polytetrafluoroethylene having a pore diameter of 0.1 to 5 μm, for example, 1 μm, polyethylene terephthalate or polyethylene fabric having a pore diameter of 0.1 to 5 μm, for example, 1 μm, and the like can be given.

  In the cellulose non-woven fabric used in the present invention, it is preferable that water in cellulose is finally replaced with an organic solvent such as alcohol in a film-forming process by filtration. In this method, water is removed by filtration, and an organic solvent such as alcohol is added when the cellulose content reaches 5 to 99% by weight. Alternatively, the organic dispersion such as alcohol can be replaced with the organic solvent such as alcohol at the end of the filtration by introducing the cellulose dispersion into the filtration apparatus and then gently introducing an organic solvent such as alcohol onto the dispersion.

  The organic solvent such as alcohol used here is not particularly limited. For example, in addition to alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol, acetone, methyl ethyl ketone, tetrahydrofuran, cyclohexane 1 type, or 2 or more types of organic solvents, such as toluene and carbon tetrachloride. When using a water-insoluble organic solvent, it is preferable to use a water-soluble organic solvent or a mixed solvent with the water-soluble organic solvent, and then replace with a water-insoluble organic solvent.

(Chemical modification of nonwoven fabric)
As described above, the chemical modification of the nonwoven fabric may be performed after the nonwoven fabric is manufactured and replaced with an organic solvent such as alcohol and then the nonwoven fabric is further dried or not dried. This is preferable because the reaction rate of chemical modification is increased. In the case of drying, it may be blown dry, dried under reduced pressure, or dried under pressure. Moreover, you may heat.
The chemical modification of the non-woven fabric can take a normal method. That is, chemical modification can be performed by reacting cellulose of the nonwoven fabric with a chemical modifier according to a conventional method. At this time, if necessary, a solvent or a catalyst may be used, or heating, decompression, or the like may be performed. As the catalyst, it is preferable to use a basic catalyst such as pyridine, triethylamine, sodium hydroxide or sodium acetate, or an acidic catalyst such as acetic acid, sulfuric acid or perchloric acid.

As the temperature condition, if it is too high, there is a concern about a decrease in the degree of polymerization of cellulose, and if it is too low, the reaction rate decreases, so 40 to 130 ° C. is preferable. The reaction time is several minutes to several tens of hours depending on the chemical modifier and the chemical modification rate.
After performing chemical modification in this way, it is preferable to wash thoroughly with water in order to terminate the reaction. If the unreacted chemical modifier remains, it is not preferable because it causes a problem when it is combined with the resin. In addition, after sufficiently washing with water, the remaining water is preferably replaced with an organic solvent such as alcohol. In this case, the nonwoven fabric can be easily replaced by immersing it in an organic solvent such as alcohol.

(Dry)
After such chemical modification, the nonwoven fabric is finally dried, but may be blown dry or dried under reduced pressure, or may be dried under pressure. Moreover, you may heat-dry. When heating, the temperature is preferably 50 ° C or higher, more preferably 80 ° C or higher, 250 ° C or lower is more preferable, and 150 ° C or lower is more preferable. If the heating temperature is too low, drying may take time or drying may be insufficient, and if the heating temperature is too high, cellulose may be decomposed. Moreover, when pressurizing, 0.01 MPa or more is preferable, 0.1 MPa or more is more preferable, 5 MPa or less is preferable, and 1 MPa or less is more preferable. If the pressure is too low, drying may be insufficient, and if the pressure is too high, the cellulose nonwoven fabric may be crushed or decomposed.

[(B) Modified polyolefin having functional group]
The modified polyolefin having a functional group as component (B) may have a functional group in the main chain of the olefin polymer, or directly or as a side chain in the main chain of the olefin polymer. It may have a functional group bonded via a divalent group. Especially, what has a functional group through a bivalent group as a side chain in the principal chain of an olefin type polymer is especially preferable.

(B) Modified polyolefin which has a functional group may be used individually by 1 type, and may use 2 or more types together.

  The molecular weight of the modified polyolefin is preferably 2,000 or more, more preferably 5,000 or more in terms of the weight average molecular weight Mw measured by GPC (Gel Permeation Chromatography) and converted by the calibration curve of each polyolefin. It is particularly preferably 10,000 or more, more preferably 1,000,000 or less, more preferably 500,000 or less, and particularly preferably 200,000 or less. As Mw is higher than the lower limit, stickiness decreases, and the adhesion to the polyolefin of component (C) tends to increase, and as the Mw is lower than the upper limit, the viscosity decreases and the solution tends to be easily prepared or melted. is there. The GPC measurement is performed by a conventionally known method using a commercially available apparatus using orthodichlorobenzene or the like as a solvent.

  The molecular weight distribution Mw / Mn represented by the ratio of the weight average molecular weight Mw and the number average molecular weight Mn of the modified polyolefin is not particularly limited, but is usually 1 or more, usually 20 or less, preferably 15 or less, more preferably Is 10 or less.

  The modified polyolefin having a functional group can be obtained by adding a functional group to an olefin polymer as a precursor. Alternatively, as described later, it can also be produced by copolymerizing an α-olefin and an ethylenically unsaturated monomer having a functional group.

(1) Olefin polymer as a precursor As the olefin polymer as a precursor, for example, homopolymers of α-olefin having about 2 to 8 carbon atoms such as ethylene, propylene, 1-butene; α-olefin, ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 1-hexene, 4-methyl Binary or ternary copolymers with other α-olefins having about 2 to 18 carbon atoms such as -1-hexene, 1-heptene, 1-octene, 1-decene, 1-octadecene, etc. It is done.

  More specifically, for example, ethylene homopolymers such as branched low-density polyethylene and linear high-density polyethylene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-propylene-1-butene Ethylene resins such as copolymers, ethylene-4-methyl-1-pentene copolymers, ethylene-1-hexene copolymers, ethylene-1-heptene copolymers, ethylene-1-octene copolymers; propylene Propylene resins such as homopolymers, propylene-ethylene copolymers, propylene-ethylene-1-butene copolymers; 1-butene homopolymers, 1-butene-ethylene copolymers, 1-butene-propylene copolymers 1-butene resin such as coalescence; 4-methyl-1-pentene homopolymer, 4-methyl-1-pentene-ethylene copolymer, etc. -1-resins such as pentene resins.

  Further, α-olefin, 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 6-methyl-1,5-heptadiene, 1,4-octadiene, 7 -Methyl-1,6-octadiene, cyclohexadiene, cyclooctadiene, dicyclopentadiene, 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-butylidene-2-norbornene, 5-isopropenyl-2 -Binary or ternary copolymers with non-conjugated dienes such as norbornene. Examples of the ternary copolymer include olefin rubbers such as an ethylene-propylene-nonconjugated diene copolymer and an ethylene-1-butene-nonconjugated diene copolymer.

Two or more of these olefin polymers may be used in combination.
Among these, ethylene resins and propylene resins are preferable, propylene resins are more preferable, ethylene-propylene copolymers and propylene homopolymers are further preferable, and propylene homopolymers are most preferable.

(2) Functional group The functional group of the modified polyolefin is preferably a polarizable group capable of forming an anion or cation. An anion or a cation can be formed or a polarizable group interacts with a functional group of the cellulose fiber to bond the cellulose fiber and the olefin resin. Examples of the group capable of forming an anion include an oxygen atom-containing group, a sulfur atom-containing group, a phosphorus atom-containing group, and a halogen atom-containing group. Examples of the group capable of forming a cation include a nitrogen atom-containing group.

  Specific examples of the functional group include, for example, carboxyl group, carboxylic anhydride group, carboxylic ester group, hydroxyl group, epoxy group, amide group, ammonium group, nitrile group, amino group, imide group, isocyanate group, and acetyl group. Thiol group, ether group, thioether group, sulfone group, phosphone group, nitro group, urethane group, halogen atom and the like. These functional groups may have 2 or more types. Among these, a carboxyl group, a carboxylic acid anhydride group, a carboxylic acid ester group, a hydroxyl group, an ammonium group, an amino group, an imide group, and an isocyanate group are preferable, and a carboxylic acid anhydride group and an ammonium group are more preferable.

  The divalent group in the case where these functional groups are present as side chains on the main chain of the olefin polymer via a divalent group is not particularly limited. Specifically, for example, a linear, branched or cyclic aliphatic hydrocarbon group having about 1 to 20 carbon atoms such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a phenylene group, a naphthylene group, etc. And an alkyleneoxy group having about 1 to 20 carbon atoms such as an aromatic hydrocarbon group, methyleneoxy group, ethyleneoxy group, trimethyleneoxy group, and tetramethyleneoxy group.

  The amount of the functional group of the modified polyolefin is preferably 0.1 equivalent or more, more preferably 0.2 equivalent or more, particularly preferably 0.4 equivalent or more, as an average equivalent per molecule of the olefin polymer. The amount is preferably 10 equivalents or less, more preferably 5 equivalents or less, and particularly preferably 3 equivalents or less. If the amount of the functional group is less than the above range, the interaction between the modified polyolefin and the cellulose nonwoven fabric tends to be weak, whereas if the amount exceeds the above range, the function of the modified polyolefin as an adhesive between the cellulose nonwoven fabric and the polyolefin tends to be impaired. It becomes.

(3) Method for producing a modified polyolefin having a functional group (B) As a method for producing a modified polyolefin having a functional group, any conventional method such as the following methods (i) to (v) may be employed.

(I) A method of graft-reacting an ethylenically unsaturated monomer having a functional group to an olefin polymer
(ii) A method in which an α-olefin is copolymerized with an ethylenically unsaturated monomer having a functional group protected with a protective group as necessary, and then the protective group is removed.
(iii) A trifunctional or higher polyfunctional monomer is allowed to react with the olefin polymer by radical polymerization or the like, and the polyolefin chain is bonded to the main chain of the olefin polymer by the polyfunctional monomer. How to add functional groups
(iv) A method of adding a functional group as a side chain to the main chain of the olefin polymer by a method of reacting a functional group-containing compound, etc. (v) Oxidation by heating the olefin polymer in the presence of molecular oxygen A carbonyl is produced at the terminal of the olefin polymer, and the carbonyl is reduced to a hydroxyl group by a reducing agent under an inert atmosphere.

  Hereinafter, the methods (i) and (ii) will be described in detail as specific examples.

(I) A method of grafting an ethylenically unsaturated monomer having a functional group to an olefin polymer The graft reaction of an ethylenically unsaturated monomer having a functional group to an olefin polymer is, for example, a radical In the presence of a generating agent, a conventional method such as a melt grafting method in a molten state of an olefin polymer and a solution grafting method in a solution state with an organic solvent can be used.

(I-1) Ethylenically unsaturated monomer having a functional group As the ethylenically unsaturated monomer having a functional group to be graft-reacted on an olefin polymer, a carboxyl group, a carboxylic acid anhydride group, a carboxylic acid ester An ethylenically unsaturated monomer having a group, a hydroxyl group, an epoxy group, an amide group, a nitrile group, an amino group, an imide group, an isocyanate group, an acetyl group, or the like can be used.

Examples of the ethylenically unsaturated monomer having a carboxyl group as a functional group include (meth) acrylic acid [where “(meth) acryl” is “acryl” or / and “methacryl”. Shall mean. The same applies to “(meth) acrylate” and the like. ], Crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid and the like.
Examples of the ethylenically unsaturated monomer having a carboxylic acid anhydride group include maleic anhydride, itaconic anhydride, and citraconic anhydride.
Examples of the ethylenically unsaturated monomer having a carboxylic acid ester group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate.
Examples of the ethylenically unsaturated monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropyl (meth) acrylate, and 2-hydroxymethyl-3-hydroxy. Examples include propyl (meth) acrylate, 2,2-dihydroxymethyl-3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.
Examples of the ethylenically unsaturated monomer having an epoxy group include glycidyl (meth) acrylate, propyl glycidyl maleate, butyl glycidyl maleate, propyl glycidyl fumarate, and butyl glycidyl fumarate.
Examples of the ethylenically unsaturated monomer having an amide group include (meth) acrylamide.
Examples of the ethylenically unsaturated monomer having a nitrile group include (meth) acrylonitrile.
Examples of the ethylenically unsaturated monomer having an amino group include aminoethyl (meth) acrylate.
Examples of the ethylenically unsaturated monomer having an imide group include maleic imide.
Examples of the ethylenically unsaturated monomer having an isocyanate group include 2-isocyanatoethyl (meth) acrylate, (meth) acryloyl isocyanate, vinyl isocyanate, isopropenyl isocyanate and the like.
Examples of the ethylenically unsaturated monomer having an acetyl group include vinyl acetate and the like.
These may be used alone or in combination of two or more.

(I-2) Radical generator Specific examples of the radical generator include di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, and 2,5-dimethyl-2,5. Dialkyl such as di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 1,3-bis (t-butylperoxyisopropyl) benzene Peroxides: t-butyl peroxyacetate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, 2,5 -Dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylpa) -Oxy) peroxyesters such as hexyne-3; diacyl peroxides such as 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide; t-butyl hydroperoxide, cumene hydroperoxide , Hydroperoxides such as diisopropylbenzene hydroperoxide and 2,5-dimethyl-2,5-di (hydroperoxy) hexane; organic peroxides such as methyl peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide Or 2,2′-azobisisobutyronitrile, 2,2′-azobis (isobutyramide) dihalide, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide] Azodi-t-buta Azo compounds, etc. and the like.
Two or more of these radical generators may be used in combination.

(I-3) Reaction method The grafting reaction can be carried out by a melting method or a solution method.

In the melting method, the grafting reaction can be performed using a kneader such as a single-screw or twin-screw extruder, a horizontal twin-screw stirrer such as a horizontal twin-screw multi-disc device, a vertical stirrer such as a double helical ribbon stirrer, or the like. .
In this case, the ethylenically unsaturated monomer having the functional group is usually 0.005 parts by weight or more, preferably 0.1 parts by weight with respect to 100 parts by weight of the olefin polymer and the olefin polymer. The radical generator is usually 0.001 part by weight or more, preferably 0.01 part by weight or more, and usually 10 parts by weight or less, preferably 20 parts by weight or less, preferably 10 parts by weight or less. 5 parts by weight or less are reacted.
The reaction is usually carried out for about 0.5 to 10 minutes by melting the olefin polymer at a temperature of usually 100 ° C. or higher and usually 300 ° C. or lower, preferably 200 ° C. or lower.

In the solution method, the olefin polymer and an ethylenically unsaturated monomer having the functional group with respect to 100 parts by weight of the olefin polymer are usually added to an aromatic solvent such as toluene, xylene, or chlorobenzene. 0.1 parts by weight or more, preferably 3 parts by weight or more, and usually 100 parts by weight or less, preferably 50 parts by weight or less, and the radical generator is usually 0.5 parts by weight or more, preferably 1 part by weight or more, and Usually, 50 parts by weight or less, preferably 30 parts by weight or less is added.
The reaction is usually performed for about 0.1 to 8 hours by dissolving the olefin polymer at a temperature of about 80 to 140 ° C.
The concentration of the reaction system (the total concentration of the olefin polymer, ethylenically unsaturated monomer and radical generator in the solution) should be about 5 to 60% by weight from the viewpoint of reaction efficiency and handleability. preferable.

(ii) A method of copolymerizing an α-olefin and an ethylenically unsaturated monomer having a functional group protected with a protective group as required, and then removing the protective group Olefin polymer and necessary The copolymerization with an ethylenically unsaturated monomer having a functional group protected with a protective group can be carried out by solution polymerization, slurry polymerization or bulk polymerization in the presence of a catalyst system.

(Ii-1) α-Olefin Preferred examples of the α-olefin to be used for copolymerization include α-olefins having about 2 to 8 carbon atoms such as ethylene, propylene, and 1-butene. These may be used alone or in combination of two or more.

(Ii-2) Ethylenically unsaturated monomer having a functional group Examples of the ethylenically unsaturated monomer having a functional group include a carboxyl group, a carboxylic acid anhydride group, a carboxylic acid ester group, a hydroxyl group, an epoxy group, and an amide. An ethylenically unsaturated monomer having a group, nitrile group, amino group, imide group, isocyanate group, acetyl group or the like can be used.
In order to prevent these functional groups from deactivating the catalyst system described later, the functional groups are protected with a trialkylsilyl group, a dialkylaluminum group or the like as necessary to prevent the reaction between the functional group and the catalyst. .

  Examples of the ethylenically unsaturated monomer having a functional group include (meth) acrylic acid [wherein “(meth) acrylic” represents an ethylenically unsaturated monomer having a carboxyl group as a functional group. "Means" acrylic "or / and" methacrylic ". ], Crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid and the like.

  Examples of the ethylenically unsaturated monomer having a carboxylic acid anhydride group include maleic anhydride, itaconic anhydride, and citraconic anhydride.

  Examples of the ethylenically unsaturated monomer having a carboxylic acid ester group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate.

  Examples of the ethylenically unsaturated monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropyl (meth) acrylate, and 2-hydroxymethyl-3-hydroxy. Examples include propyl (meth) acrylate, 2,2-dihydroxymethyl-3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.

  Examples of the ethylenically unsaturated monomer having an epoxy group include glycidyl (meth) acrylate, propyl glycidyl fumarate, butyl glycidyl maleate, propyl glycidyl fumarate, and butyl glycidyl fumarate.

  Examples of the ethylenically unsaturated monomer having an amide group include (meth) acrylamide.

  Examples of the ethylenically unsaturated monomer having a nitrile group include (meth) acrylonitrile.

  Examples of the ethylenically unsaturated monomer having an amino group include aminoethyl (meth) acrylate.

Examples of the ethylenically unsaturated monomer having an imide group include maleic imide.
Examples of the ethylenically unsaturated monomer having an isocyanate group include 2-isocyanatoethyl (meth) acrylate, (meth) acryloyl isocyanate, vinyl isocyanate, isopropenyl isocyanate and the like.

  Examples of the ethylenically unsaturated monomer having an acetyl group include vinyl acetate and the like.

  These may be used alone or in combination of two or more.

(Ii-2) Catalyst system Copolymerization of the α-olefin and the ethylenically unsaturated monomer having the functional group can be performed using, for example, the following catalyst systems (x) and (y).

(X) An α-olefin polymerization catalyst comprising the following components (a), (b) and (c) and optionally a component (d).
Component (a): Metallocene compound Component (b): Organoaluminum oxy compound, component (a) reacts with component (a)
From ionic compounds or Lewis acids that can be converted to cations
Compound selected from the group consisting of: Component (c): Chain transfer agent Component (d): Fine particle carrier

(Y) An α-olefin polymerization catalyst characterized by comprising the following components (a), (c) and (e) and optionally a component (f).
Ingredient (a): Metallocene compound Ingredient (c): Chain transfer agent Ingredient (e): Group consisting of ion-exchangeable layered compound excluding silicate or inorganic silicate
Selected compound Component (f): Organoaluminum compound

In the above catalyst systems (x) and (y), (a) a known metallocene compound can be appropriately selected and used.
(C) Although it does not specifically limit as a chain transfer agent, Hydrogen is used suitably.
(D) As the fine particle carrier, known ones such as silica, alumina, silica-alumina and the like can be used.

(Ii-3) Reaction method Although the system of the copolymerization reaction of an α-olefin and an ethylenically unsaturated monomer having a functional group is not particularly limited, solution, slurry and bulk polymerization are preferred.

  Specific examples of the solvent at the time of solution or slurry polymerization include carbonization such as n-pentane, n-hexane, n-heptane, n-octane, n-decane, benzene, toluene, xylene, cyclohexane, methylcyclohexane, and dimethylcyclohexane. Hydrogens; halogenated hydrocarbons such as chloroform, methylene chloride, carbon tetrachloride, tetrachloroethane, chlorobenzene, o-dichlorobenzene; polar solvents such as n-butyl acetate, methyl isobutyl ketone, tetrahydrofuran, cyclohexanone, dimethyl sulfoxide And the like. Of these, hydrocarbons are preferable, and aromatic hydrocarbons are particularly preferable. Moreover, you may use as a mixed solvent of the solvent described here.

  The catalyst concentration is not particularly limited. For example, when the reaction method is solution polymerization, the metallocene compound concentration is usually 100 g or less, preferably 50 g or less, and most preferably 25 g or less with respect to 1 L of the reaction solution. Usually, it is 0.01 mg or more, preferably 0.05 mg or more, and most preferably 0.1 mg or more.

The polymerization temperature, polymerization pressure, and polymerization time are not particularly limited, but usually optimum settings can be made in consideration of productivity and process capability from the following ranges.
That is, the polymerization temperature is usually −20 ° C. or higher, preferably 0 ° C. or higher, and is usually 150 ° C. or lower, preferably 100 ° C. or lower.
The polymerization pressure is usually 0.01 MPa or more, preferably 0.05 MPa or more, most preferably 0.1 MPa or more, and is usually 100 MPa or less, preferably 20 MPa or less, and most preferably 5 MPa or less.
The polymerization time is usually 0.1 hours or more, preferably 0.2 hours or more, most preferably 0.3 hours or more, and usually 30 hours or less, preferably 25 hours or less, more preferably 20 hours or less, most Preferably it is 15 hours or less.

[(C) Polyolefin]
Examples of the polyolefin as the component (C) include the same olefin polymers as the precursor of the (B) modified polyolefin.
The olefin polymer preferably has a molecular weight of 2,000 or more, more preferably 5,000 or more, and particularly preferably 10,000 or more in terms of weight average molecular weight Mw. Further, it is preferably 1,000,000 or less, more preferably 800,000 or less, and particularly preferably 600,000 or less. If Mw is smaller than the above lower limit, it tends to be brittle, and if it is larger than the upper limit, molding tends to be difficult. The molecular weight distribution Mw / Mn is not particularly limited, but is usually 1 or more, preferably 2 or more, and is usually 10 or less, preferably 7 or less, more preferably 5 or less.

  (C) An olefin polymer may be used individually by 1 type, and may use 2 or more types together.

[Ratio of each component]
The content ratio of each component in the cellulose / polyolefin composite material of the present invention is preferably such that the content ratio of the cellulose nonwoven fabric with respect to the total of the components (A) to (C) is 1% by weight or more. % Is more preferable, and it is particularly preferable to be 10% by weight or more. Further, it is preferably 95% by weight or less, more preferably 85% by weight or less, and particularly preferably 80% by weight or less. When the content ratio of the cellulose nonwoven fabric is less than the above lower limit value, the intended purpose of improving the physical properties by cellulose nonwoven fabric blending as a cellulose / polyolefin composite material tends not to be sufficiently expressed, whereas, when the above upper limit value is exceeded, The moldability as a cellulose / polyolefin composite material tends to deteriorate.

Further, the content of the modified polyolefin having a functional group is preferably 0.1% by weight or more, particularly 1% by weight or more, particularly 2% by weight or more, and 95% by weight or less, particularly 80% by weight or less, It is preferable that it is 70 weight% or less. If the content of the modified polyolefin having a functional group is less than the lower limit, the adhesive effect of the modified polyolefin cannot be sufficiently secured, and if the upper limit is exceeded, various physical properties of the composite material are lowered.
The cellulose nonwoven fabric content in the cellulose / polyolefin composite material of the present invention is determined by the weight of the cellulose nonwoven fabric before contacting with the resin and the weight of the cellulose nonwoven fabric composite material after the lamination with the polyolefin in the method for producing the cellulose / polyolefin composite material of the present invention described later. It can be determined from the weight of the composite material. Further, there are a method for obtaining from the specific gravity of the resin and a method for obtaining by quantitatively determining the functional groups of the resin and cellulose using NMR and IR. The modified polyolefin content in the cellulose / polyolefin composite material can be determined in the same manner.

[Other ingredients]
The cellulose / polyolefin composite material of the present invention may contain components other than the components (A) to (C) as necessary.
As other components that may be contained in the cellulose / polyolefin composite material of the present invention, various additives usually used in polyolefin resin compositions, for example, antioxidants, light stabilizers, ultraviolet absorbers, Examples include nucleating agents, neutralizing agents, lubricants, antiblocking agents, dispersants, fluidity improvers, mold release agents, flame retardants, foaming agents, colorants, fillers, and the like. The proportion is usually 60% by weight or less based on the total of the components (A) to (C).
For the purpose of eliminating the generation of ash during combustion, it is desirable to reduce the content of inorganic fillers and inorganic fibers as much as possible.

[Linear expansion coefficient]
The cellulose / polyolefin composite material of the present invention is preferably a low linear expansion coefficient composite material having a linear expansion coefficient of 130 ppm / K or less. This linear expansion coefficient is more preferably 120 ppm / K or less. However, the linear expansion coefficient is usually 10 ppm / K or more.

{Method for producing cellulose / polyolefin composite material}
The cellulose / polyolefin-based composite material of the present invention can be produced using the components (A) to (C) and the above-mentioned additives that are added as necessary, but preferably (A) a cellulose nonwoven fabric. (B) The modified polyolefin having a functional group is contacted by dipping or coating, and (C) the polyolefin is bonded together.

The method for contacting the cellulose nonwoven fabric with the modified polyolefin having a functional group is not particularly limited as long as the surface of the cellulose nonwoven fabric can be covered with the modified polyolefin as a result.
In particular,
(I) A method of immersing a cellulose nonwoven fabric in a modified polyolefin solution in which a modified polyolefin having a functional group is dissolved
(ii) A method of applying a modified polyolefin solution in which a modified polyolefin having a functional group is dissolved to a cellulose nonwoven fabric
(iii) A method of immersing a cellulose nonwoven fabric in a melted modified polyolefin melt having a functional group
(iv) A method of applying a modified polyolefin melt having a functional group in a molten state to a cellulose nonwoven fabric may be mentioned.

(I) Method of immersing cellulose nonwoven fabric in modified polyolefin solution in which modified polyolefin having functional group is dissolved First, the modified polyolefin having a functional group is dissolved in an organic solvent capable of dissolving it. Specific examples of the organic solvent used here include hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, n-decane, benzene, toluene, xylene, cyclohexane, methylcyclohexane, and dimethylcyclohexane. , Halogenated hydrocarbons such as chloroform, methylene chloride, carbon tetrachloride, tetrachloroethane, chlorobenzene and o-dichlorobenzene, polar solvents such as n-butyl acetate, methyl isobutyl ketone, tetrahydrofuran, cyclohexanone and dimethyl sulfoxide. Can be mentioned. These organic solvents may be used individually by 1 type, and may be used as a 2 or more types of mixed solvent. Of these, hydrocarbons are preferred as the solvent.
The dissolution temperature is not particularly limited, but the dissolution is performed at a temperature between room temperature and the boiling point of the solvent.
The concentration of the modified polyolefin in the modified polyolefin solution is not particularly limited as long as the modified polyolefin can be dissolved, but a concentration of 1% by weight or more is usually preferable. If the concentration is lower than that, it is difficult for the cellulose nonwoven fabric to be coated with the modified polyolefin. Usually, the modified polyolefin concentration of the modified polyolefin solution is about 1 to 50% by weight.
The immersion time is usually 0.1 seconds or longer, preferably 1 second or longer, and 10 minutes or shorter, preferably 5 minutes or shorter. Moreover, you may repeat immersion twice or more. When the immersion is repeated, it may be dried every time or may not be dried. After the last immersion, the film is sufficiently dried so that no solvent remains. The drying may be air drying, or a hot air dryer, a vacuum dryer or the like may be used.

(ii) Method of applying a modified polyolefin solution in which a modified polyolefin having a functional group is dissolved to a cellulose nonwoven fabric First, a modified polyolefin having a functional group is dissolved in an organic solvent capable of dissolving it. The organic solvent used here and its solution concentration are the same as in (i) above.
Although there is no restriction | limiting in particular in the method of apply | coating modified polyolefin solution to a cellulose nonwoven fabric, A conventionally well-known method, such as the method of apply | coating with a spray, the method of apply | coating with a roller, the method of applying with a brush, can be used. Application may be repeated two or more times. When application is repeated, it may be dried every time or may not be dried. After the last application, it is sufficiently dried so that no solvent remains. The drying may be air drying, or a hot air dryer, a vacuum dryer or the like may be used.

(iii) Method of immersing cellulose nonwoven fabric in a modified polyolefin melt having a functional group in a molten state When a cellulose nonwoven fabric is immersed in a modified polyolefin melt having a functional group in a molten state, Heat to melt.
The immersion time of the cellulose nonwoven fabric in the modified polyolefin melt is usually 0.1 seconds or longer, preferably 1 second or longer, and 10 minutes or shorter, preferably 5 minutes or shorter. Moreover, you may repeat immersion twice or more. When the immersion is repeated, it may be cooled and solidified every time or may not be solidified.

(iv) A method of applying a modified polyolefin melt having a functional group in a molten state to a cellulose nonwoven fabric When applying a modified olefin copolymer to a cellulose nonwoven fabric in a molten state, the modified polyolefin is applied in the same manner as in (iii) above. Melt.
Although there is no restriction | limiting in particular in the application method of the modified polyolefin melt to a cellulose nonwoven fabric, The method similar to the method used by said (ii) can be mentioned.

  Thus, after making a modified polyolefin adhere and coat to a cellulose nonwoven fabric, in order to improve both adhesiveness, you may heat-press. In this case, the hot pressing conditions vary depending on the type of the modified polyolefin used, but it is usually preferable to carry out at 50 to 300 ° C. and 0.1 to 10 MPa.

The cellulose / polyolefin composite material of the present invention can be obtained by laminating a polyolefin to a cellulose nonwoven fabric having a modified polyolefin having a functional group attached thereto as described above. In this case, in order to obtain good adhesiveness, it is preferable to heat the cellulose nonwoven fabric to which the modified polyolefin is adhered together with the polyolefin. Although there is no restriction | limiting in particular in heating temperature, Considering practicality, 50-300 degreeC, Especially 60-250 degreeC is preferable. For the bonding, a stamping molding method, a sheet mold compound (SMC), a press molding method, or the like is used.
In any method, the cellulose non-woven fabric is coated by dipping or applying a modified polyolefin having a functional group to form a prepreg in a dry-to-touch state. The prepreg has a thickness of about 20 μm to 1 mm in advance. The cellulose / polyolefin composite material of the present invention is preferably bonded to a polyolefin formed into a film or sheet. When the prepreg is bonded to the polyolefin film or sheet by hot pressing, the hot pressing conditions vary depending on the type of modified polyolefin and polyolefin used, but it is usually preferable to carry out at 50 to 300 ° C. and 0.1 to 15 MPa. .
A plurality of the composite materials obtained may be laminated. In this case, any type of molding apparatus may be used.

{Usage}
The cellulose / polyolefin composite material of the present invention can be used as a structural material by taking advantage of its low linear expansion coefficient, high elasticity, high strength and the like. In particular, it is suitably used as an automobile material such as an automobile interior material, an outer plate, a bumper, etc., a housing for household electric products, a home appliance part, a packaging material, a building material, a civil engineering material, a fishery material, and other industrial materials.

  Hereinafter, the present invention will be described more specifically with reference to production examples, examples, and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

  The method for measuring the linear expansion coefficient and adhesion of the cellulose / polyolefin composite material of the present invention, the method for measuring the physical properties of polyolefin, the method for calculating the chemical modification rate of the cellulose nonwoven fabric, and the like are as follows.

(1) Graft rate 200 mg of the polymer and 4800 mg of chloroform were placed in a 10 ml sample bottle and heated at 50 ° C. for 30 minutes for complete dissolution. Chloroform was placed in a liquid cell having a material NaCl and an optical path length of 0.5 mm as a background. Next, the dissolved polymer solution was placed in a liquid cell, and an infrared absorption spectrum was measured using FT-IR460plus manufactured by JASCO Corporation at a total number of 32 times. The graft ratio of maleic anhydride was calculated using a calibration curve prepared by measuring a solution of maleic anhydride in chloroform. Then, from the area of the absorption peak of the carbonyl group (maximum peak in the vicinity of 1780 cm ⁻¹ , 1750 to 1813 cm ⁻¹ ), the acid component content in the polymer is calculated based on a separately prepared calibration curve, and this is calculated as the graft ratio ( % By weight).

(2) Linear expansion coefficient The composite material was cut into a 3 mm width x 40 mm length by a laser cutter. This was stretched using a TII TMA120 made of SII at a chucking distance of 20 mm, a load of 10 g, and a nitrogen atmosphere from room temperature to 180 ° C. at 5 ° C./min. At 180 ° C. to 25 ° C. 5 ° C./min. At 25 ° C to 180 ° C, 5 ° C / min. The linear expansion coefficient was determined from the measured value from 60 ° C. to 100 ° C. during the second temperature increase.

(3) Adhesiveness After attaching cello tape (trade name: manufactured by Nichiban Co., Ltd.) to both surfaces of the film-like composite material sample, both of them were quickly pulled in the 180 ° direction. This was repeated 5 times. The case where the polyolefin film (polypropylene film) on the surface was not peeled once was marked with ○, and the case where it was peeled once was marked with ×.

これを解いていくと、以下の通りである。

(4) Chemical modification rate of cellulose nonwoven fabric 0.5 g of cellulose nonwoven fabric is precisely weighed, and 6 ml of methanol and 2 ml of distilled water are added thereto. This is stirred at 60-70 ° C. for 30 minutes, and then 10 ml of 0.05N aqueous sodium hydroxide solution is added. The mixture is stirred at 60 to 70 ° C. for 15 minutes and further stirred at room temperature for one day. This is titrated with 0.02N aqueous hydrochloric acid using phenolphthalein.
Here, from the amount Z (ml) of the 0.02N hydrochloric acid aqueous solution required for the titration, the number of moles Q of the substituent introduced by chemical modification is obtained by the following formula.
Q (mol) = 0.05 (N) × 10 (ml) / 1000
−0.02 (N) × Z (ml) / 1000
The relationship between the number of moles Q of the substituent and the chemical modification rate X (mol%) is calculated by the following formula (cellulose = (C ₆ O ₅ H ₁₀ ) _n = (162.14) _n , repetition Number of hydroxyl groups per unit = 3, molecular weight of OH = 17). In the following, T is the molecular weight of the substituent.

Solving this, it is as follows.

[Production Example 1: Production of cellulose nonwoven fabric]
Wood flour (Miyashita Wood Co., Ltd., Yonematsu 100) was degreased with a 2% by weight aqueous solution of sodium carbonate at 80 ° C. for 6 hours. This was washed with demineralized water and then delignified with sodium chlorite under acetic acid acidity at 80 ° C. for 5.5 hours. After washing with desalted water, it was further immersed in a 5% by weight aqueous solution of potassium hydroxide for 16 hours to dehemicellulose. After washing with demineralized water, the suspension was made into a 0.5 wt% water suspension, and passed through an ultrahigh pressure homogenizer (Ultimizer manufactured by Sugino Machine) 10 times at 245 MPa.

The obtained cellulose dispersion was diluted with water to a concentration of 0.2% by weight, and 100 g was put into a 90 mm diameter filter using PTFE having a pore diameter of 1 μm. When the solid content became about 5% by weight, 2-propanol Was replaced. Then, it press-dried at 120 degreeC and 0.14 MPa for 5 minutes, and obtained the cellulose nonwoven fabric.
This cellulose nonwoven fabric was impregnated with 100 ml of acetic anhydride and heated at 120 ° C. for 7 hours. Thereafter, it was thoroughly washed with distilled water, and finally immersed in 2-propanol for 10 minutes, and then press-dried at 120 ° C. and 0.14 MPa for 5 minutes to obtain an acetylated cellulose nonwoven fabric having a thickness of 55 μm. The chemical modification rate of this nonwoven fabric was 42 mol%.

[Production Example 2: Production of maleic anhydride-modified polypropylene]
100 parts by weight of an isotactic polypropylene homopolymer having a melt flow rate (MFR) of 10 g / 10 minutes (measured at 230 ° C./21.18 N), 19 parts by weight of maleic anhydride, and 720 parts by weight of monochlorobenzene as an organic solvent The mixture was charged in a glass flask equipped with a stirrer, a thermometer, a reflux condenser and a dropping funnel and dissolved at 130 ° C. under a nitrogen atmosphere. 10 parts by weight of dicumyl peroxide, which is an organic peroxide, was added from the dropping funnel at the same temperature, and the reaction was continued at the same temperature for 4 hours to be reacted. After completion of the reaction, the reaction system was cooled to near room temperature and then added to acetone prepared in advance at 10 ° C. to precipitate a polymer. The precipitated polymer was separated by filtration, and the polymer was washed by repeating precipitation and separation with acetone in the same manner. The washed polymer was dried under reduced pressure to obtain a white powdery polymer. The graft ratio of the maleic anhydride-modified polypropylene thus obtained was 3.3% by weight, and the melt flow rate (MFR) was 950 g / 10 min.

[Example 1]
20 g of maleic anhydride-modified polypropylene obtained in Production Example 2 was dissolved in 180 g of toluene at 80 ° C. Here, the cellulose nonwoven fabric 20 mm × 50 mm (59.4 mg) obtained in Production Example 1 was dipped for 3 seconds, pulled up and air-dried for 1 minute. This was repeated 5 times and dried at 20 ° C. for 45 minutes. This was preheated at 160 ° C. for 1 minute and then pressed at 160 ° C. and 5 MPa for 1 minute. Then, the cellulose nonwoven fabric / modified polypropylene composite film was obtained by cooling at room temperature and 5 MPa for 1 minute.
Separately, a commercially available polypropylene (manufactured by Nippon Polypropylene Co., Ltd .: MA1, MFR nominal 21 g / 10 min according to JIS K7210: 1999) was formed into a 100 μm thick film by hot pressing.
The cellulose nonwoven fabric / modified polypropylene composite film was sandwiched between the two polypropylene films thus obtained and preheated at 190 ° C. for 1 minute, and then pressed at 190 ° C. and 5 MPa for 1 minute. Then, the film which consists of 59.4 mg of cellulose, 15.8 mg of modified polypropylene, and 117.2 mg of polypropylene was obtained by cooling at room temperature and 5 MPa for 1 minute. The linear expansion coefficient of the obtained film was measured. Also, an adhesion test was performed. The results are shown in Table 1.

[Comparative Example 1]
The linear expansion coefficient of a commercially available polypropylene film obtained in the same manner as in Example 1 was measured, and the results are shown in Table 1.

[Comparative Example 2]
The maleic anhydride-modified polypropylene obtained in Production Example 2 was preheated at 160 ° C. for 1 minute, and then pressed at 160 ° C. and 5 MPa for 1 minute. Then, a modified polypropylene film having a thickness of 100 μm was obtained by cooling at room temperature and 5 MPa for 1 minute. The linear expansion coefficient of the obtained film was measured, and the results are shown in Table 1.

[Comparative Example 3]
The cellulose nonwoven fabric obtained in Production Example 1 was sandwiched between two commercially available polypropylene films obtained in the same manner as in Example 1, preheated at 190 ° C. for 1 minute, and then pressed at 190 ° C. and 5 MPa for 1 minute. Then, the composite material film which consists of cellulose nonwoven fabric 40.0mg and polypropylene 130.2mg was obtained by cooling at room temperature and 5 Mpa for 1 minute. The linear expansion coefficient of the obtained film was measured. Also, an adhesion test was performed. The results are shown in Table 1.

  From the results of Example 1 and Comparative Examples 1 to 3, the cellulose / polyolefin composite material of the present invention comprising cellulose fiber, a modified polyolefin having a functional group, and a polyolefin exhibits a low linear expansion coefficient and each component is strong. It was revealed that the film was adhered to the film. In addition, since a cellulose fiber is organic substance, even if it burns, since an ash is not generate | occur | produced substantially, it is advantageous to thermal recycling.

Claims (1)

(A) A cellulose nonwoven fabric that does not contain a cellulose fiber having a fiber diameter of 1500 nm or more as a cellulose fiber, (B) a modified polyolefin having a functional group, and (C) a cellulose / polyolefin composite material containing a polyolefin ,
The content of the cellulose nonwoven fabric (A) is 10 to 80% by weight,
(B) A cellulose / polyolefin composite material in which the modified polyolefin having a functional group is a maleic anhydride-modified polyolefin and / or a polyolefin containing a cationic group .