JP2020193262A - Resin molding - Google Patents

Abstract

To provide a resin molding having cellulose fiber dispersed in a thermoplastic resin, the resin molding having excellent continuous productivity and showing excellent impact resistance.SOLUTION: A resin molding is obtained by molding a cellulose fiber dispersion resin composite having cellulose fiber dispersed in a thermoplastic resin. The resin molding has a wall thickness of 0.1 mm or more. The cellulose fiber dispersion resin composite contains aggregate of the cellulose fiber. At least part of the aggregate is aggregate with an area of 2.0×104-2.0×105 μm2 in plan view.SELECTED DRAWING: None

Description

The present invention relates to a resin molded product in which cellulose fibers are dispersed in a thermoplastic resin.

A fiber-reinforced resin in which fibers such as glass fiber, carbon fiber, and cellulose fiber are blended with the resin is known in order to enhance the mechanical properties of the resin product.
When glass fiber is used, glass fiber, which is a nonflammable inorganic substance, remains as ash in a large amount even when burned by thermal recycling or the like, and there is a problem in the energy recovery rate in recycling. Further, the specific gravity of the glass fiber is larger than that of the resin, and there is a problem that the weight of the fiber reinforced resin increases. Further, glass fiber has a larger heat capacity than resin, so that it takes time to cool and solidify after molding, and as a result, there is a limitation in improving the production efficiency of resin products.
Further, the above problem can be solved by using carbon fiber instead of glass fiber. However, carbon fiber is expensive, and there is a problem that the cost of the resin product increases when it is used.

On the other hand, cellulose fibers are lightweight, have a small amount of combustion residue in thermal recycling and the like, and are relatively inexpensive, so that they are advantageous in terms of weight reduction, recyclability, cost and the like.
Techniques related to fiber reinforced plastics using cellulose fibers have been reported.
For example, Patent Document 1 describes a method for producing a plant fiber-containing resin composition in which the fiber raw material of the plant fiber is dispersed in the resin composition in a sufficiently fine state and in the absence of coarse plant fiber aggregates. It is disclosed. In this production method, a thermoplastic resin, a plant fiber composition containing plant fibers having a specific shape, and a plant fiber modifier are compounded while being melt-kneaded.
Further, Patent Document 2 describes a method for producing a fiber-containing resin composition, which can suppress coloring due to heat, can enhance the dispersibility of fine cellulosic fibers in a polyolefin resin, and has excellent mechanical properties. It is disclosed. This production method has fine cellulose fibers, water, a polar group-containing polyolefin resin having a reactive functional group, a low molecular weight compound having a hydrophobic group and a hydrophilic group, and a reactive functional group and a hydrophilic group. No polyolefin-based resin is heat-kneaded at 100 ° C. or higher and devolatile.
Further, Patent Document 3 describes cellulose-reinforced thermoplastic, which is a composite resin in which a thermoplastic synthetic resin, cellulose, and an ionic compound are kneaded in a specific amount ratio and finely divided plant fibers are uniformly dispersed in the thermoplastic resin. It is stated that the resin was obtained. In the examples of Patent Document 3, it is described that the area of the cellulose aggregates in the thermoplastic resin can be reduced to a predetermined area of 19121 μm ² or less.

Japanese Unexamined Patent Publication No. 2014-193959 JP-A-2015-209439 International Publication No. 2017/170745

Resin molded bodies having various shapes are molded using fiber reinforced plastics using cellulose fibers. However, if the resin molded product using the cellulose fiber reinforced resin is made into a complicated shape or a shape having a thin wall portion (for example, a portion having a wall thickness of 1 mm or less), the moldability or productivity (yield) is not sufficient. It has become clear that there is.
For example, a hole may be formed in the thin-walled portion of the molded product having the thin-walled portion. Further, when injection molding a resin molded body using a cellulose fiber reinforced resin, the molten resin material may break in a spool (passage through which the molten resin material flows), and if the break occurs, the upstream side (fixed) It is necessary to remove the residue solidified on the mold side), which makes it difficult to continuously produce the target molded product.
Further, the fiber-reinforced resin molded product using cellulose fibers does not always exhibit sufficient mechanical properties, and further improvement of mechanical properties such as impact characteristics is desired.
The present invention is a resin molded product in which cellulose fibers are dispersed in a thermoplastic resin, and is continuously produced even when it has a portion having a wall thickness of 0.1 mm or more and a thin portion. An object of the present invention is to provide a resin molded product having excellent properties and excellent impact resistance.

As described in Patent Document 3, the cellulose fibers form not a little aggregates in the resin. In view of the above problems, the present inventors have investigated the relationship between the state of the agglomerates and the above-mentioned problems of moldability or productivity. As a result, in the cellulose fiber-dispersed resin composite material used as a constituent material of the resin molded product, the size of the aggregates of the cellulose fibers in the composite material is not simply reduced as described in Patent Document 3. By controlling the resin composition so as to contain agglomerates of a specific size, the fluidity of the resin composition can be effectively increased, and as a result, the thickness of the resin molded product obtained by molding the resin composition without defects. It has been found that a portion of 0.1 mm or more can be more reliably applied, and that this resin molded product is also excellent in continuous productivity. Furthermore, the present inventors have found that the resin molded product is also excellent in impact resistance, and have completed the present invention.

That is, the above problem was solved by the following means.
[1]
A resin molded product obtained by molding a cellulose fiber-dispersed resin composite material in which cellulose fibers are dispersed in a thermoplastic resin.
The resin molded body has a wall thickness of 0.1 mm or more.
The cellulose fiber-dispersed resin composite contains agglomerates of the cellulose fibers, and at least a part of the agglomerates has an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ^{2 in} a plan view. A resin molded body that is an agglomerate.
[2]
At least a part of the cellulose fiber agglomerates contained in the cellulose fiber-dispersed resin composite material is an agglomerate having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ^{2 in} a plan view [1]. ] The resin molded body described in.
[3]
Aggregates of cellulose fibers contained in the cellulose fiber dispersion resin composite is a 1.0 × 10 ⁷ μm aggregates of less than ² area in a plan view, a resin molding according to [1] or [2] body.
[4]
The resin molded product according to any one of [1] to [3], which has at least a portion having a wall thickness of 1 mm or less.
[5]
The resin molded product according to any one of [1] to [4], which contains a cellulose fiber having a fiber length of 0.3 mm or more.
[6]
The resin molded product according to any one of [1] to [5], which contains a cellulose fiber having a fiber length of 0.8 mm or more.
[7]
The resin according to any one of [1] to [6], wherein the content of the cellulose fiber determined by the following measurement method in the cellulose fiber-dispersed resin composite material is 1% by mass or more and less than 70% by mass. Molded body.
<Measurement method>
A sample of the cellulose fiber-dispersed resin composite material is subjected to thermogravimetric analysis (TGA) at a heating rate of + 10 ° C./min under a nitrogen atmosphere, and the content of the cellulose fiber is calculated by the following [Equation 1].
[Formula 1] (Cellulose fiber content [mass%]) = (mass reduction of sample between 200 and 380 ° C. [mg]) x 100 / (mass [mg] of sample before thermogravimetric analysis )
[8]
The resin molded product according to any one of [1] to [7], wherein the content of the cellulose fibers in the cellulose fiber-dispersed resin composite material is 5% by mass or more and less than 50% by mass.
[9]
The thermoplastic resins are polyolefin resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin, polyamide resin, polyvinyl chloride resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polystyrene resin, and 3-. The resin molded product according to any one of [1] to [8], which is any one or more of the hydroxybutyrate-co-3-hydroxyhexanoate polymer resins.
[10]
The resin molded product according to any one of [1] to [9], wherein the thermoplastic resin is a polyolefin resin.
[11]
The resin molded product according to any one of [1] to [10], which contains aluminum.
[12]
The resin molded product according to [10], wherein the polyolefin resin contains one or more of a low-density polyethylene resin, a high-density polyethylene resin, and a polypropylene resin.
[13]
In any one of [1] to [11], the composite material is a polyolefin resin composition containing any one or more of carbon black, a light stabilizer, and an inorganic powder having a refractive index of 2 or more. The resin molded product described.
[14]
The resin molded product according to any one of [1] to [13], wherein the resin molded product is a product having an annular structure or a multi-divided product having a ring structure.
[15]
The resin molded body according to any one of [1] to [14], wherein the resin molded body is a joint member or an end member for a corrugated tube having a wavy shape in the longitudinal direction.
[16]
The molded product according to any one of [1] to [15], wherein the resin molded product is an injection molded product.
[17]
The resin molded product according to any one of [1] to [16], wherein at least a part of the constituent material is derived from a recycled material.
[18]
The resin molded product according to any one of [1] to [17], which is a member for civil engineering, building materials, or automobiles.

In the present invention, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

The molded product of the present invention is excellent in manufacturing efficiency and also in impact resistance.

FIG. 1 is a graph showing the area distribution of agglomerates of cellulose fibers contained in the composite material in one embodiment of the composite material. FIG. 2 is a schematic view of a simulated part for a wire harness protector. FIG. 2A is a right side view, FIG. 2B is a front view, and FIG. 2C is a plan view. FIG. 3 is a schematic view of a corrugated pipe end member. FIG. 3A is a front view, and FIG. 3B is a right side view. FIG. 4 is a schematic view of the joint member. FIG. 4A is a front view, and FIG. 4B is a right side view.

A preferred embodiment of the present invention will be described.

The resin molded product of the present invention (hereinafter, also simply referred to as “molded product of the present invention”) uses a cellulose fiber-dispersed resin composite material obtained by dispersing cellulose fibers in a thermoplastic resin as a constituent material, and this composite material is used as a constituent material. It is a fiber-reinforced resin molded product that is molded. The molded product of the present invention has a wall thickness of 0.1 mm or more. The cellulose fiber-dispersed resin composite contains agglomerates of the cellulose fibers, and at least a part of the agglomerates has an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ² in plan view. It is a thing.
With such a configuration, the molded product of the present invention exhibits excellent impact resistance characteristics (impact strength). Further, the molded product of the present invention is excellent in formability in its production, and when obtained by injection molding, for example, a spool (passage through which a composite material injected from an injection molding machine flows) or a runner (composite connecting molds). The molding material is less likely to break in the passage through which the material flows. That is, the molded product of the present invention has excellent continuous productivity and a high yield. The molded product of the present invention exhibits the above-mentioned characteristics even when it has a thin-walled portion.

First, the cellulose fiber-dispersed resin composite material constituting the resin molded product will be described. In the following, the description of the size of the aggregates of the cellulose fibers constituting the composite material is applied as it is to the size of the aggregates of the cellulose fibers constituting the molded product. That is, in a molded product (injection molded product, press molded product, etc.) obtained by molding a composite material, the size of the cellulose fiber agglomerates is substantially the same as the size of the cellulose fiber agglomerates of the composite material. is there.

[Cellulose fiber dispersion resin composite material]
In the cellulose fiber-dispersed resin composite material (hereinafter, also simply referred to as “composite material”), cellulose fibers are dispersed in a thermoplastic resin, and the composite material contains agglomerates of the cellulose fibers. At least a part of the agglomerates is an agglomerate having an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ² in plan view. Further, the composite material may be in a form containing an inorganic substance such as aluminum, various additives and the like depending on the type of raw material used.

-Cellulose fiber-
As described above, the composite material contains agglomerates of cellulose fibers. At least some of these individual aggregates have an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ² in plan view. By forming the composite material in a form containing such agglomerates, it is possible to enhance the impact resistance characteristics as compared with the form containing simply cellulose fibers. Further, even if the molded product has a thin-walled portion, continuous productivity or yield can be effectively increased. Here, μm ² means (μm) ² . From this viewpoint, it is preferable that at least a part of the agglomerates of the cellulose fibers is an agglomerate having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ^{2 in} a plan view, and at least agglomerates of the cellulose fibers. It is more preferable that a part of the agglomerates has an area of 5.0 × 10 ^{4 to} 1.0 × 10 ⁵ μm ^{2 in} a plan view.
In the present invention, when the size such as "area" or "major axis diameter" of agglomerates is simply described, it is the size for each agglomerate. Further, in the present specification, the term "area in plan view" or simply "area" of the agglomerate means the area when the composite material is viewed in plan from one direction. This also applies to the "semi-major axis". The specific measurement method will be described later.

In the present invention, the agglomerates of cellulose fibers are usually agglomerates formed by entwining cellulose fibers with each other, but depending on the raw material used, some of the raw material-derived components may be mixed. When the agglomerates are dispersed in the composite material, the agglomerates are scattered in the composite material and are observed as scattered objects. When the content of the cellulose fibers in the composite material is high, the overlap of the cellulose fibers is large, so that the discrimination of the aggregates of the cellulose fibers may not be clear. In such a case, by diluting the composite material with a resin of the same type (same type) as the resin constituting the composite material, the aggregates of the cellulose fibers can be made to stand out, and the aggregates can be clearly observed. can do. Usually, the composite material is in the form of a sheet, and agglomerates of cellulose fibers can be observed as dark-colored portions of transmitted light. Further, when the resin portion of the composite material is dark due to the influence of a coloring material such as carbon black or a coloring component, agglomerates of cellulose fibers can be observed as a light-colored portion of reflected light.

More specifically, the area of the cellulose fiber agglomerates contained in the composite material is analyzed by taking a microscopic image of the composite material as a thin film sheet (for example, a thickness of 0.1 mm) with reflected light or transmitted light. Can be determined by In addition, when the amount of cellulose fibers in the composite material is large, the overlap of the cellulose fibers dispersed in the resin is remarkable as it is, and it is not easy to distinguish and observe the overlap between the cellulose fibers and the agglomerates. Is also assumed. Even in this case, the composite material is mixed with a resin having compatibility with the resin constituting the composite material (preferably a resin of the same type as the resin constituting the composite material) and diluted by kneading to thin the diluted product. A sheet (for example, 0.1 mm in thickness) can be used, and the sheet can be observed under a microscope to take a microscopic image to more reliably determine the area of agglomerates.
The thin film sheet can be prepared by slicing or pressing the composite material. Note that the presence of 1.0 × 10 ⁷ μm ² or more large aggregates, even without the thin sheet, also without diluting the composite can be determined by observing the surface of the composite.

In the present invention, the observation of agglutination may be easier to see, for example, when the concentration of cellulose fibers is diluted to a certain range. The case of a 3-7% concentration of cellulose fibers diluted to composite, in a plan view observation, occupies the observation area, the 3.0 × ¹⁰ 4 ~1.3 × ^{10 5} aggregates the area the The ratio s1 of the total area is preferably 0.01 to 1.0%. In this case, s1 is more preferably 0.015 to 0.8%, further preferably 0.015 to 0.7%, and preferably 0.018 to 0.6%. The ratio of the observed area and the total area of the agglomerates having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ^{2 to} the observed area is the method (s1) described in Examples described later. It is determined by the measurement method).
The total area of agglomerates in the observed area changes depending on the dilution of the composite material. For example, in an actual observation, the content of the cellulose fiber is 5 as the ratio of the total area of the agglomerates having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ^{2 to} the observed area s1 ′. The value (5% conversion value) sr1 converted into the observation result of the sample (thin film sheet) obtained by diluting the composite material so as to be% can be calculated by the following formula.

sr1 [%] = s1'[%] x 5 [mass%] / (cellulosic fiber content [mass%] of the sample to be observed)

The sr1 is preferably 0.01 to 1.0%, more preferably 0.015 to 0.8%, further preferably 0.015 to 0.7%, and 0.018 to 0.6%. Is also preferable.

Further, when the composite material is diluted to make the concentration of the cellulose fibers 3 to 7%, the area of 1.0 × 10 ^{3 to} 1.0 × 10 ⁶ μm ² occupies the observed area in the plan view observation. The ratio s2 of the total area of the agglomerates is preferably 0.015 to 1.5%, more preferably 0.02 to 1.2%, further preferably 0.02 to 1.0%, and 0.03. It is also preferable to set it to ~ 1.0%. The ratio of the observed area and the total area of the agglomerates having an area of 1.0 × 10 ^{3 to} 1.0 × 10 ⁶ μm ^{2 to} the observed area is determined by the method (s2) described in Examples described later. It is determined by the measurement method).
For example, in actual observation, the content of cellulose fibers is 5 as the ratio s2'of the total area of the agglomerates having an area of 1.0 × 10 ^{3 to} 1.0 × 10 ⁶ μm ^{2 to} the observed area. The value (5% conversion value) sr2 converted into the observation result of the sample (thin film sheet) obtained by diluting the composite material so as to be% can be calculated by the following formula.

sr2 [%] = s2'[%] x 5 [mass%] / (cellulosic fiber content [mass%] of the sample to be observed)

The sr2 is preferably 0.015 to 1.5%, more preferably 0.02 to 1.2%, further preferably 0.02 to 1.0%, and 0.03 to 1.0%. Is also preferable.

The morphology of the agglomerates of the cellulose fibers contained in the composite material has various morphologies and cannot be uniquely specified, but any agglomerates of the cellulose fibers are sufficient, and at least a part of them has a major axis diameter of 1.6 × 10. It is preferably ^{2 to} 5.0 × 10 ² μm. Semimajor axis means the maximum diameter in plan view observed in individual aggregates. That is, in the image observed with a microscope as described above, the distance when the distance from one point to another point on the outer circumference of the agglomerate is the maximum is defined as the semimajor axis diameter. By forming the composite material in a form containing such agglomerates, the impact resistance characteristics of the composite material can be further enhanced. From this point of view, it is more preferable that at least a part of the aggregate of the cellulose fiber is an aggregate having a major axis diameter of 1.6 × 10 ^{2 to} 4.0 × 10 ² μm in the composite material.

Composites contain aggregates of cellulose fibers in the street area specific range described above, and the area of the aggregates of the respective cellulosic fibers contained in the composite is 1.0 × 10 ⁷ in a plan view It is preferably less than μm ² . Area of agglomerates by a 1.0 × 10 ⁷ [mu] m less than ^2, it is possible to further enhance the impact strength and moldability of the composite material. From the viewpoint of moldability, it is more preferable area of aggregates of cellulose fibers contained in the composite material is less than 3.0 × 10 ⁶ μm ^2. On the other hand, agglomerates having an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ² , which are essential components of the composite material, contribute to the improvement of impact resistance characteristics as described later. It is also thought to affect the improvement of liquidity.

Of the aggregates of cellulose fibers contained in the composite material, the total area of the aggregates having an area of 1.0 × 10 ^{3 to} 1.0 × 10 ⁶ μm ² (area is 1.0 × 10 ³ to 1). .. Sum of the areas of individual agglomerates in the range of 0 × 10 ⁶ μm ² ) Sum of the areas of agglomerates of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ² in s2 The ratio of (s1 / s2) × 100) of the total area of individual aggregates having an area in the range of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ² ) is 10 to 95%. preferable. By setting this ratio to 10% or more, the impact resistance characteristics can be further enhanced, and the balance between the impact resistance characteristics and the moldability can be made more preferable. From this point of view, the above ratio is more preferably 20% or more, further preferably 40% or more. It is technically difficult to increase the above ratio to a high degree. Considering this point, it is practical that the above ratio is 90% or less, and usually 80% or less. The above ratio is particularly preferably 40 to 80%.

The cellulose fibers dispersed in the composite material preferably contain cellulose fibers having a fiber length of 0.3 mm or more. By containing cellulose fibers having a fiber length of 0.3 mm or more, mechanical strength such as impact strength can be further improved. From this point, the composite material preferably contains a cellulose fiber having a fiber length of 0.5 mm or more, more preferably 0.8 mm or more, still more preferably 1 mm or more.

Further, in the composite material, the length-weighted average fiber length of the cellulose fibers is preferably 0.3 mm or more. When the length-weighted average fiber length is 0.3 mm or more, the mechanical strength such as impact resistance can be further improved. From this point, the length-weighted average fiber length of the cellulose fibers is more preferably 0.4 mm or more, still more preferably 0.5 mm or more. The upper limit of the length-weighted average fiber length is not particularly limited, but is preferably 1.3 mm or less. Here, the length-weighted average fiber length is the pulp defined in ISO 16065 2001 (JIS P8226 2006) with respect to the dissolution residue (insoluble matter) of the composite material when the composite material is immersed in a soluble solvent of the resin component. It is determined by the fiber length measurement method by the optical automatic analysis method. For example, when the resin constituting the composite material is a polyolefin resin, the length-weighted average fiber length can be determined by the same measurement method for the dissolution residue (insoluble matter) in hot xylene (130 to 150 ° C.). it can. The length-weighted average fiber length is the sum of the squares of the fiber lengths of each fiber used for measurement divided by the total of the measured fiber lengths. The characteristics of this average are that the influence of the fiber length of the fiber having a long fiber length and the influence of the probability density of the fiber longer than the number average fiber length are larger than those of the number average fiber length which is a simple average of the fiber lengths. Therefore, it is more suitable than the number average fiber length for evaluating the influence of the long fiber length on the mechanical properties of the composite material in the fibers contained in the composite material.
The average fiber diameter of the cellulose fibers in the composite material is preferably 5 to 40 μm. When the cellulose fiber has the above-mentioned fiber length and the above-mentioned fiber diameter, the mechanical strength of the obtained molded product can be further increased. Further, by setting the average fiber diameter of the cellulose fibers to 5 μm or more, the pretreatment of the cellulose material becomes unnecessary, and the processing load in the preparation of the composite material described later can be reduced. Further, by setting the average fiber diameter of the cellulose fibers to 40 μm or less, even a molded product having a thin wall portion can be obtained with good moldability. The average fiber diameter of the cellulose fibers in the composite material is preferably 10 to 30 μm.

The composite material preferably has a cellulose fiber content of 1% by mass or more in the composite material. The mechanical strength can be improved by setting the content of the cellulose fibers in the composite material to 1% by mass or more. From this point of view, the content of the cellulose fiber in the composite material is more preferably 3% by mass or more, further preferably 5% by mass or more, still more preferably 7% by mass or more, and particularly preferably 9% by mass or more. is there. Further, in consideration of further improving the bending strength, the content of the cellulose fibers in the composite material is preferably 25% by mass or more.
The composite material preferably has a cellulose fiber content of less than 70% by mass. By setting the content of the cellulose fibers in the composite material to less than 70% by mass, it becomes easy to obtain a composite material in which the cellulose fibers are uniformly dispersed by melt-kneading. From the viewpoint of further suppressing water absorption, the content of the cellulose fibers in the composite material is preferably less than 50% by mass, and more preferably less than 40% by mass.
The composite material preferably has a cellulose fiber content of 1% by mass or more and less than 70% by mass, more preferably 3% by mass or more and less than 70% by mass, and 5% by mass or more and less than 50% by mass. Is more preferably 7% by mass or more and less than 40% by mass, and 9% by mass or more and less than 40% by mass is particularly preferable.

The content (mass%) of the cellulose fibers contained in the composite material is determined by adopting the value obtained by thermogravimetric analysis as described below.

<Method of determining the content of cellulose fibers (effective mass ratio of cellulose)>
A composite sample (10 mg) previously dried at 80 ° C. for 1 hour in an air atmosphere was subjected to thermogravimetric analysis (TGA) from 23 ° C. to 400 ° C. at a heating rate of + 10 ° C./min in a nitrogen atmosphere. The content of cellulose fibers (also referred to as mass% or effective mass ratio of cellulose) is calculated by the following [Formula 1].

[Formula 1] (Cellulose fiber content [mass%]) = (mass reduction of composite sample between 200 and 380 ° C. [mg]) x 100 / (composite in dry state before thermogravimetric analysis) Material sample mass [mg])

When the temperature is raised to 200 to 380 ° C. at a temperature rising rate of + 10 ° C./min in a nitrogen atmosphere, the cellulose fibers are substantially thermally decomposed and disappear. In the present invention, the mass% calculated by the above [Equation 1] is regarded as the content of the cellulose fibers contained in the composite material. However, some of the cellulose fibers may remain in this temperature range without disappearing, but if the temperature range is exceeded, for example, the resin component disappears or the heat decomposition weight loss occurs when a high temperature decomposable compound coexists. And the residual components cannot be distinguished, making it difficult to measure the amount of cellulose fibers. Therefore, in the present invention, the mass% calculated by [Equation 1] is used for grasping the amount of cellulose fibers, but the relationship between the amount of cellulose fibers thus obtained and the mechanical properties of the composite material is related. Is high.

-Thermoplastic resin-
The thermoplastic resin constituting the cellulose fiber-dispersed resin composite material of the present invention is not particularly limited, and can be widely applied as long as it can be injection-molded. As an example, polyolefin resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), acrylonitrile-styrene copolymer resin (AS resin), polyamide resin (for example, nylon), polyvinyl chloride resin, polyethylene terephthalate resin, poly Thermoplastic biodecomposition of butylene terephthalate resin, thermoplastic resin such as polystyrene resin, 3-hydroxybutyrate-3-hydroxyhexanoate polymer resin (PHBH resin), polybutylene succinate resin, polylactic acid resin, etc. Examples include sex resins. One type of thermoplastic resin may be used alone, or two or more types may be used in combination.

Examples of the polyolefin resin include polyethylene resin, polypropylene resin, and a mixture (blended resin) of polyethylene and polypropylene. Further, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-glycidyl methacrylate copolymer, etc. Ethylene-based copolymers of the above, or mixtures containing these, can also be mentioned as polyolefin resins. One type of polyolefin resin may be used alone, or two or more types may be used in combination. The polyolefin resin is preferably a polyethylene resin and / or a polypropylene resin, and more preferably a polyethylene resin.
Examples of the polyethylene resin include low density polyethylene (LDPE) and high density polyethylene (HDPE). The polyethylene resin is preferably low density polyethylene. The polyethylene resin is also preferably high density polyethylene.
The low density polyethylene has a density means the polyethylene of less than 880 kg / ^{m 3} or more 940 kg / ^{m 3.} The high-density polyethylene means polyethylene having a density higher than that of the low-density polyethylene.
The low-density polyethylene may be a so-called "low-density polyethylene" or "ultra-low-density polyethylene" having long-chain branches, and is a linear low-density polyethylene obtained by copolymerizing ethylene with a small amount of α-olefin monomer. LLDPE) may be used, and further, it may be an “ethylene-α-olefin copolymer elastomer” included in the above density range.
The polyolefin resin preferably contains one or more of a low-density polyethylene resin, a high-density polyethylene resin, and a polypropylene resin.
The polyolefin resin may be acid-modified with an unsaturated carboxylic acid or a derivative thereof, which is usually used.

The composite material may contain a plurality of resin components. For example, a polyethylene resin such as a copolymer of ethylene and α-olefin, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, an ethylene-propylene copolymer, or a polybutene in a polyethylene resin and / or a polypropylene resin. And / or it may contain a polyolefin resin other than the polypropylene resin.
Further, the composite material may contain, for example, a polyolefin resin and polyethylene terephthalate and / or nylon. In this case, the total amount of polyethylene terephthalate and / or nylon is preferably 10 parts by mass or less with respect to 100 parts by mass of the polyolefin resin.

The thermoplastic resin constituting the composite material used in the present invention preferably contains a polyolefin resin, more preferably polyethylene, and particularly preferably low-density polyethylene. It is also preferable that the thermoplastic resin is a polyolefin resin.
Further, the thermoplastic resin is preferably a combination of low-density polyolein and an ethylene-acrylic acid copolymer, and a combination of low-density polyethylene, high-density polyethylene and an ethylene-vinyl acetate copolymer is also preferable.

-Other ingredients-
The composite material is also preferably in the form of aluminum dispersed in the thermoplastic resin in addition to the cellulose fibers (the dispersed individual aluminum is also referred to as an aluminum dispersoid). In the composite, aluminum can have a flaky structure and / or an irregularly folded structure of a thin film.
When aluminum is dispersed in the composite material, the content of aluminum is preferably 1% by mass or more and 30% by mass or less in the composite material. By setting the content of aluminum within this range, the workability of the composite material can be further improved, and lumps of aluminum are less likely to occur during processing of the composite material.

When the composite material contains aluminum, it is preferable that the aluminum contains an aluminum dispersoid having a maximum XY length of 0.005 mm or more. The ratio of the number of aluminum dispersoids having a maximum XY length of 1 mm or more to the number of aluminum dispersoids having a maximum XY length of 0.005 mm or more is preferably less than 1%. By setting this ratio to less than 1%, the workability of the composite material can be further improved, and lumps of aluminum are less likely to occur during the processing of the composite material.
The maximum XY length is determined by observing the cross section and surface of a layer (for example, layer (A)) formed by using a composite material. Specifically, on this observation surface, a straight line is drawn with respect to the aluminum dispersoid in one random direction (X-axis direction), and the maximum distance connecting the two intersections where the straight line and the outer circumference of aluminum intersect is the maximum. The distance (maximum length on the X-axis) is measured, and a straight line is drawn in the direction perpendicular to the specific direction (Y-axis direction), and the distance connecting the two intersections where this straight line and the outer circumference of aluminum intersect is The maximum distance (Y-axis maximum length) is measured, and the longer of the X-axis maximum length and the Y-axis maximum length is defined as the XY maximum length. The maximum XY length can be determined using image analysis software.
In the present invention, the aluminum dispersoid dispersed in the composite material preferably has an average maximum XY length of 0.02 to 0.2 mm, more preferably 0.04 to 0.1 mm. .. The average of the maximum XY lengths is the average of the maximum XY lengths measured by using image analysis software.

Taking the case where the thermoplastic resin in the composite material is a polyolefin resin as an example, the content (mass%) of the polyolefin resin and the content (mass%) of aluminum can be determined as follows.
The content (mass%) of the polyolefin resin in the composite material can be calculated from the following formula as the thermal xylene dissolved mass ratio Ga (mass%). The method for determining the hot xylene dissolved mass ratio will be described later.
Ga [mass%] = {(W0-Wa) / W0} x 100
W0: Dry mass of composite material before immersion in hot xylene Wa: Mass of composite material after immersion in hot xylene at 138 ° C. and dry removal of xylene Here, the composite material is a polyolefin resin, cellulose fiber, and When composed of other components such as aluminum, the content (% by mass) of the other components such as aluminum in the composite material is indicated by the following.
Content of other components such as aluminum (mass%) = 100-{(effective mass ratio of cellulose (mass%) + content of polyolefin resin (% by mass)}
The content (% by mass) of aluminum in the composite material is indicated by the following when the component other than the cellulose fiber, the polyolefin resin and the aluminum is not contained, or even if it is contained, it is negligible.
Aluminum content (mass%) = 100-{(cellulose effective mass ratio (mass%) + polyolefin resin content (mass%)}

− Thermal xylene dissolved mass ratio −
If the types of resins that can be mixed in the composite material are known, the amount of each resin can be determined based on the thermal xylene dissolved mass ratio of the composite material.
In the present invention, the hot xylene dissolved mass ratio is determined as follows.
In accordance with the cross-linking degree measurement of the automobile electric wire standard JASOD618, 0.1 to 1 g of a composite molded sheet is cut out as a sample, this sample is wrapped in 400 mesh stainless mesh, and immersed in 100 ml of xylene at a predetermined temperature for 24 hours. To do. The sample is then pulled up and then dried in vacuum at 80 ° C. for 24 hours. From the mass of the sample before and after the test, the thermal xylene dissolved mass ratio G (%) is calculated from the following formula.
G = {(W0-W) / W0} x 100
W0: Mass of dry composite material before immersion in hot xylene W: Mass of composite material after immersion in hot xylene and dry removal of xylene

For example, assume that the polyolefin resin constituting the composite material is composed of a polyethylene resin and a polypropylene resin. When the mass ratio of hot xylene dissolved at 138 ° C. is Ga (%) and the mass ratio of hot xylene dissolved at 105 ° C. is Gb (%), Ga is the mass ratio (%) of the polyolefin resin, and Ga-Gb. Corresponds to the mass ratio (%) of the polypropylene resin, and Gb corresponds to the mass ratio (%) of polyethylene.
That is, the content of the polyolefin resin in the composite material can be determined as the above-mentioned thermal xylene dissolved mass ratio Ga (%) at 138 ° C.
here,
Ga = {(W0-Wa) / W0} x 100
Gb = {(W0-Wb) / W0} × 100
W0: Mass of dry composite material before immersion in hot xylene Wa: Mass of composite material after immersion in hot xylene at 138 ° C. and dry removal of xylene Wb: Mass of composite material after immersion in hot xylene at 105 ° C. and then dry xylene Mass of composite after removal

At least a part of the above-mentioned thermoplastic resin and cellulose fiber constituting the composite material can be derived from the recycled material. Further, at least a part of aluminum, polyethylene terephthalate and / or nylon which can be contained in the composite material can be derived from the recycled material. By using the recycled material, the manufacturing cost of the composite material can be suppressed.
Examples of the recycled material include a polyolefin laminated paper having a paper and a polyolefin thin film layer, a polyolefin laminated paper having a paper, a polyolefin thin film layer and an aluminum thin film layer, and a beverage pack and / or a food pack made of these processed papers. And so on.
More preferably, a polyolefin thin film piece to which cellulose fibers are attached (hereinafter, "cellulose fibers" obtained by treating the above-mentioned laminated paper and / or beverage / food pack with a pulper and peeling off the paper portion to remove the paper portion. It is also preferable to use "adhered polyolefin thin film piece") as a recycled material. When the laminated paper or the beverage / food pack has an aluminum thin film layer, aluminum is also attached to the cellulose fiber-attached polyolefin thin film piece.
Even when such a recycled material is used as a raw material, excellent moldability can be realized by controlling agglomerates of cellulose fibers (adopting a method of melt-kneading in the presence of water as described later). In addition, the mechanical properties of the obtained molded product can be effectively enhanced.

The composite material preferably has a water content of less than 1% by mass.
The above moisture content is the mass reduction rate when thermogravimetric analysis (TGA) is performed from 23 ° C. to 120 ° C. at a heating rate of + 10 ° C./min within 6 hours after the production of the composite material in a nitrogen atmosphere. By mass%).

The composite material may contain an inorganic material. Bending elasticity, impact resistance, and flame retardancy can be improved by containing an inorganic material. Examples of the inorganic material include calcium carbonate, talc, clay, magnesium oxide, aluminum hydroxide, magnesium hydroxide, titanium oxide and the like. The inorganic material preferably has a refractive index of 2 or more. Examples of the inorganic material having a refractive index of 2 or more include titanium oxide. The inorganic agent is preferably contained in the form of an inorganic powder.

The composite material may contain a fibrous material other than the cellulose fiber. Examples of fibrous materials other than cellulose fibers include glass fibers, ceramic fibers, carbon fibers, and resin fibers other than cellulose fibers. Examples of resin fibers other than cellulose fibers include aramid fibers and polyparaphenylene benzobisoxazole (PBO) fibers. As the glass fiber, chopped strand and milled fiber are preferable.

The composite material may contain a flame retardant, an antioxidant, a stabilizer (including a light stabilizer), a weather resistant agent, a compatibilizer, an impact improver, a modifier, and the like, depending on the purpose. Examples of the light stabilizer include polymethylpropyl 3-oxy- [4 (2,2,6,6 tetramethyl) piperidinyl] siloxane and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol. Polyester with succinic acid, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazin-2,4-diyl} {(2,2,6,6-) Examples thereof include hindered amine compounds such as tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}]. Further, in order to improve workability, an oil component and various additives can be included. Examples thereof include paraffin, modified polyethylene wax, stearate, hydroxystearate, vinylidene fluoride-based copolymer such as vinylidene fluoride / hexafluoropropylene copolymer, and organically modified siloxane.

The composite material can contain carbon black, various pigments and dyes. The composite material may also contain a metallic luster-based coloring material. In addition, a conductive component other than aluminum, such as conductive carbon black, can be contained. Further, the composite material can contain a thermal conductivity-imparting component other than aluminum.

The composite material is preferably a polyolefin resin composition containing any one or more of carbon black, a light stabilizer, and an inorganic powder having a refractive index of 2 or more.

The composite material may be crosslinked. Examples of the cross-linking agent include organic peroxides, and specific examples thereof include dicumyl peroxide. The composite material may be in the form of being crosslinked by a silane crosslinking method.

Melt flow rate of composite material (hereinafter sometimes referred to as MFR. In the present invention, unless otherwise specified, MFR is a value measured under the conditions of a temperature of 230 ° C. and a load of 5 kg in accordance with JIS-K-7210. Is not unique depending on the intended use, but is preferably 0.05 to 50 (g / 10 min), and more preferably 0.1 to 10 (g / 10 min).

[Manufacturing method of composite material]
The composite material used in the present invention can be obtained by kneading a thermoplastic resin and a cellulose fiber.
The composite material is preferably prepared as follows.
The thermoplastic resin and the cellulose fiber or its source (hereinafter, these are also collectively referred to as “cellulose material”. Details will be described later) are kneaded. By adjusting the kneading conditions at this time or adding an additive at the time of kneading, a composite material containing a cellulose aggregate of a specific size can be obtained. For example, when kneading a thermoplastic resin and a cellulose material, a composite material can be obtained by adding a polar solvent having a high affinity for cellulose fibers and kneading the material. The polar solvent preferably has a low affinity with the resin constituting the composite material. Water is suitable as the polar solvent to be added during kneading.
By controlling the amount of polar solvent added, the timing of addition, the kneading time, the kneading speed, the temperature, etc. at the time of kneading, the amount and size of the agglomerates of the cellulose fibers in the obtained composite material can be adjusted. .. For example, when the amount of water added is large, the amount of agglomerates tends to be large, and the size of agglomerates tends to be large. The control of the amount and size of agglomerates is greatly affected by the kneading time, especially in the presence of polar solvents. In order to form the agglomerates specified in the present invention, it is preferable to carry out kneading in the presence of water for a long time. For example, by adding water in a divided manner during long-term kneading, a sufficient kneading time can be secured in the presence of water. The amount and size of the agglomerates of cellulose fibers produced by this kneading tend not to change much in the kneading in the absence of water. Therefore, while the kneading conditions in the presence of water are important, the obtained composite material can maintain the aggregated state of cellulose even in the subsequent processing and blending (dilution) with the resin, and the desired impact strength and the like can be maintained. Can express the characteristics of.
In kneading, it is preferable to add the polar solvent in a plurality of times. For example, it is preferred to first knead the thermoplastic resin and the cellulose fibers in the presence of a portion of the total amount of the polar solvent and then further knead in the presence of the balance of the total amount of the polar solvent.
As the kneading device, a normal kneading device such as a kneader or a twin-screw extruder can be applied.
The above kneading is preferably melt kneading.
Here, "melt kneading" means kneading at a temperature at which the thermoplastic resin in the raw material melts. Preferably, the cellulose fibers are melt-kneaded at a temperature and treatment time at which the cellulose fibers do not deteriorate. "The cellulose fibers do not deteriorate" means that the cellulose fibers do not undergo significant discoloration, combustion, or carbonization.
The temperature in the melt-kneading (the temperature of the melt-kneaded product) is preferably 110 to 280 ° C., more preferably 130 to 220 ° C., for example, when a polyethylene resin is used.
Further, when the thermoplastic resin of the composite material is mainly composed of a polyolefin resin and further contains polyethylene terephthalate and / or nylon, for example, the total amount of polyethylene terephthalate and / or nylon is 10 parts by mass or less with respect to 100 parts by mass of the polyolefin resin. If, the melt kneading can be at the same temperature as above.

In the melt-kneading, the amount of the cellulose material used is preferably adjusted so that the content of the cellulose fibers in the obtained composite material is within the above-mentioned preferable range.

Examples of the cellulose material include those mainly composed of cellulose, and more specific examples thereof include paper, used paper, paper dust, recycled pulp, paper sludge, laminated paper, and damaged paper of laminated paper. Among them, it is preferable to use used paper and / or paper sludge from the viewpoint of cost and effective utilization of resources, and it is more preferable to use paper sludge.
This paper sludge may contain an inorganic material in addition to the cellulose fiber. From the viewpoint of increasing the elastic modulus of the composite material, paper sludge containing an inorganic material is preferable.
Here, the waste paper of the laminated paper refers to a material obtained by cutting off the extra length in the width direction and the longitudinal direction of the laminated paper generated in the manufacturing process of a beverage pack or the like. Further, when the impact strength of the composite material is important, the paper sludge preferably does not contain an inorganic material, or even if it contains an inorganic material, its content is small.
When mixing paper such as used paper, it is preferable that the paper is previously wetted with water before melt-kneading. By using the paper moistened with water, it becomes easy to obtain a composite material in which the cellulose fibers are uniformly dispersed in the resin.

When the melt-kneading is performed in the presence of water, it is preferable to remove the water as steam during the melt-kneading so that the water content of the composite material is less than 1% by mass. In this way, when the cellulose fiber-attached polyolefin thin film piece containing water is used as a raw material, the amount of energy used (power consumption) required for removing water is compared with the case where the water is removed and melt-kneaded by another process. Etc.) can be significantly suppressed.

[Resin molded product]
The molded product of the present invention is formed by molding the above-mentioned composite material. That is, the molded body of the present invention is formed by dispersing cellulose fibers in a thermoplastic resin, and contains the above-mentioned aggregates of cellulose fibers as the cellulose fibers (that is, the molded body contains aggregates of cellulose fibers. At least a part of the agglomerates is an agglomerate having an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ² ), and is a resin molded body having a wall thickness of 0.1 mm or more.
The structure of the molded body of the present invention is the same as that of the above-mentioned composite material except that it is molded into a specific shape.

The molded product of the present invention needs to have a wall thickness of 0.1 mm or more. The molded product of the present invention has a wall thickness of 0.1 mm or more and has agglomerates of cellulose fibers having a predetermined size, so that it is possible to have excellent moldability at the time of molding and sufficient mechanical strength. Become. In addition, there is no problem during molding and the moldability is excellent.
The molded product of the present invention may have a portion (thin wall portion) having a wall thickness of 1 mm or less. The thin portion may be formed over the entire molded body, or may be formed as a part of the molded body. Further, the thin-walled portion may be formed at an end portion of the molded product, or may be formed at a portion other than the end portion. The length and width of the thin portion can be, for example, preferably 0.5 mm or more, more preferably 1 mm or more, and further preferably 10 mm or more, respectively. The thin portion of the molded product of the present invention may have a portion having a wall thickness of 0.5 mm or less. Further, it may have a portion having a wall thickness of 0.2 mm or less. The lower limit of the wall thickness of the thin portion is 0.1 mm or more. The molded product of the present invention may have a portion having a wall thickness of 0.5 mm or less and 0.1 mm or more.

The structure of the molded product of the present invention is not particularly limited except that the wall thickness is 0.1 mm or more, and various structures can be used. Examples of the molded body of the present invention include molded bodies having various structures such as sheet-shaped, plate-shaped, annular (tubular), and box-shaped, and multi-divided bodies of these molded bodies. Examples of the molded product having an annular structure include a straight pipe having a substantially circular cross section and a quadrangular cross section, a curved pipe, and a corrugated pipe provided with corrugations (parts in which concave portions and convex portions are alternately arranged). Further, as a multi-divided body of a molded body having an annular structure, a multi-divided body such as a straight tube having a substantially circular cross section, a quadrangular straight tube, a curved tube, and a corrugated tube having a wavy shape is divided by half cracking or the like. A split body can be mentioned. Preferably, a molded body having an annular structure having a portion provided with waviness in the longitudinal direction, or a multi-divided body having a molded body having an annular structure having a portion provided with waviness in the longitudinal direction can be mentioned. Further, in addition to the joint member or end member of the pipe, the molded product of the present invention can be used as a member for civil engineering, building materials, automobiles, or electric wire protection.
The molded product of the present invention may be an injection molded product, an extrusion molded product, a press molded product, a blow molded product, or the like. An injection-molded article is preferable from the viewpoint of suppressing the influence on the appearance due to the content of the cellulose fiber and the manufacturability.

The molded product of the present invention is excellent in impact resistance by containing agglomerates of cellulose fibers having an area in a specific range, that is, agglomerates having an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ^2. .. Therefore, it is suitable as a molded product (resin product) that requires impact strength. Although it is not clear why the molded product of the present invention has excellent impact strength, at least a part of the cellulose fibers is cellulose having the above-mentioned specific size, preferably an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ² . It is presumed that the presence as agglomerates of fibers has a combined action of reinforcing action by cellulose fibers against high-speed deformation and an action of absorbing and mitigating impacts by agglomerates of cellulose fibers, and the impact strength is effectively enhanced. Will be done.
Further, the fluidity of the composite material is excellent by containing agglomerates of cellulose fibers having an area in a specific range, that is, agglomerates having an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ² . That is, even when the molded product has a thin portion, the continuous productivity or the yield can be effectively increased. The reason for this is not clear, but in the softened and melted state of the thermoplastic resin that requires fluidity, at least a part of the cellulose fibers has a specific size, preferably an area of 3.0 × 10 ^{4 to} 1.3. By existing as an agglomerate of × 10 ⁵ μm ² cellulose fibers, the fluidity of the resin as a matrix is ensured, and the agglomerates of the cellulose fibers themselves are deformed unlike the agglomerates of inorganic powder, for example. It is presumed that having a high degree of sexuality works comprehensively and the fluidity is enhanced.

[Manufacturing method of resin molded product]
Subsequently, a preferred embodiment of the method for producing a molded product of the present invention will be described below. The molded product of the present invention is not limited to the one obtained by the following method as long as the provisions of the present invention are satisfied.
The molded product of the present invention can be obtained by attaching the composite material used in the present invention to ordinary molding means.

The molding method of the composite material is not particularly limited, and ordinary molding methods such as injection molding, extrusion molding, press molding, and blow molding can be adopted. Injection molding is preferable from the viewpoint of imparting a complicated shape.

By doing so, the molded product of the present invention can be manufactured with good moldability by suppressing shape defects. For example, in the case of injection molding, not only is it less likely to cause shape defects, but it is also less likely to cause material breakage in spools, runners, etc., and it is excellent in moldability and productivity.
The present invention is also an invention that can contribute to reduction of environmental load.

The present invention will be further described based on examples, but the present invention is not limited to these forms. The measurement method and evaluation method of each index in the present invention are as follows.

[Cellulose fiber content in composite material]
A composite sample (10 mg) previously dried in an air atmosphere at 80 ° C. for 1 hour was subjected to thermogravimetric analysis (TGA) from 23 ° C. to 400 ° C. at a heating rate of + 10 ° C./min in a nitrogen atmosphere. The content (% by mass) of the cellulose fiber was calculated by the following [Formula 1]. Five identical composite material samples were prepared, and each composite material sample was subjected to thermal weight analysis in the same manner as described above to obtain the average value of the five values of the calculated cellulose fiber content (mass%). The average value was taken as the content (% by mass) of cellulose fibers.

[Formula 1] (Cellulose fiber content [mass%]) = (mass reduction of composite sample between 200 and 380 ° C. [mg]) x 100 / (composite in dry state before thermogravimetric analysis) Material sample mass [mg])

[Agglutination]
<Evaluation of Cellulose Fiber Aggregates-1>
The composite material was diluted with a resin to prepare a 0.1 mm thick sheet. This sheet was photographed under a microscope with transmitted light, and the size (area) and distribution of dark-colored parts (aggregates of cellulose fibers) were analyzed. The above dilution was carried out by kneading the composite material and the resin with a roll. Further, press working (press pressure: 4.2 MPa) was used for producing the sheet, and a stereomicroscope and analysis software (image analysis software Pixs2000 Pro, manufactured by inotec) were used for microscopic photography and analysis. The composite material was diluted with the above resin so that the concentration of the diluted cellulose fibers was in the range of 3 to 7% by mass. However, when agglomerates could be observed on a 0.1 mm thick sheet without diluting with resin, the agglutination was performed without dilution.
The plan-view area of the cellulose fiber aggregates analyzed as described above was evaluated according to the following evaluation criteria.

"Presence or absence of agglutinin 1":
Those with agglomerates having an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ² were rated as “yes”, and those without agglomerates were rated as “absent”.
"Presence or absence of agglutinin 1b":
Those having agglomerates having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ² were defined as “yes”, and those without agglomerates were defined as “absent”.
"Presence or absence of agglutinin 1c":
Those having agglomerates having an area of 5.0 × 10 ^{4 to} 1.0 × 10 ⁵ μm ² were defined as “yes”, and those without agglomerates were regarded as “absent”.

<Evaluation of Cellulose Fiber Aggregates-2>
Whether an area is 1.0 × 10 ⁷ [mu] m ² or more aggregates, test pieces by injection molding (thickness 4 mm, width 10 mm, length 80 mm) to prepare, and ten obtained specimen both sides of the surface Was observed and judged.
"Presence or absence of agglutinin 2":
Area is "yes" what there is 1.0 × 10 ⁷ μm ² or more of the aggregate, it was those with and without "no".

[Melt flow rate (MFR)]
The measurement was performed in accordance with JIS-K7210 under the conditions of temperature = 230 ° C. and load = 5 kg. The unit of MFR is "g / 10min".

[Impact resistance (impact strength)]
A test piece (thickness 4 mm, width 10 mm, length 80 mm) was prepared from the composite material by injection molding, and the Izod impact strength was measured using the test piece with a notch in accordance with JIS-K7110. The unit of impact resistance is "kJ / m ² ".

[Cellulose fiber length]
0.1 to 1 g was cut out from the molded sheet of the composite material, and this was used as a sample, and this sample was wrapped in a 400 mesh stainless mesh and immersed in 100 mL of xylene at 138 ° C. for 24 hours. The sample was then pulled up and then dried in vacuum at 80 ° C. for 24 hours. 0.1 g of the dry sample was sufficiently dispersed in 50 ml of ethanol, dropped onto a petri dish, and the range of 15 mm × 12 mm was observed with a microscope. Cellulose fibers with a fiber length of 0.3 mm or more are observed and no cellulose fibers with a fiber length of 0.8 mm or more are observed (○), cellulose fibers with a fiber length of 0.3 mm or more are observed, and cellulose with a fiber length of 0.8 mm or more is observed. Those in which fibers were observed were marked with (⊚), and the others were marked with (x).

[Length-weighted average fiber length]
The length-weighted average fiber length was measured by the method of measuring the fiber length by the pulp-optical automatic analysis method specified in ISO 16065 2001 (JIS P8226 2006) for the thermal xylene dissolution residue (insoluble matter) of the composite material. Specifically, 0.1 to 1 g was cut out from a molded sheet of a composite material, and this was used as a sample, and this sample was wrapped in a 400 mesh stainless mesh and immersed in 100 ml of hot xylene at 138 ° C. for 24 hours. Then, the sample was pulled up, and then the sample was dried in a vacuum at 80 ° C. for 24 hours to obtain a thermal xylene dissolution residue (insoluble matter) of the composite material. For the thermal xylene dissolution residue (insoluble matter) of this composite material, the length-weighted average fiber length was determined by a pulp-optical automatic analysis method using MORFI COMPACT manufactured by TECHPAP.

[Moldability 1]
Using a composite material, a simulated part for a wire harness protector (FIG. 2) having three thin parts having a wall thickness of 1 mm, a wall thickness of 0.7 mm, and a wall thickness of 0.5 mm is molded by injection molding to form a molded body. The moldability was evaluated.
The molding conditions of each Example and each Comparative Example were the same. Specifically, the molding conditions were a cylinder temperature of 200 ° C., a mold temperature of 40 ° C., and an injection speed of 150 mm / sec.
The shape of the simulated part is a box shape having an opening on one side of a rectangular parallelepiped having a rectangular parallelepiped inside, and has one bottom surface and four side surfaces. A plurality of protrusions are provided on the outside of the side surface of the box. The outer dimensions of the box-shaped portion 11 are height 30 mm × width 80 mm × depth 25 mm, and the wall thickness is 2 mm.
Of the plurality of protrusions, the protrusion 12 has a U-shaped roof when a side surface (80 mm × 25 mm, surface A) having the protrusion 12 is viewed in a plan view, and three walls extending in the vertical direction from the surface A. The wall thickness of the three walls is 1 mm thin (see FIG. (C)). Further, the height of the protrusion 12 in the vertical direction from the surface A is 5 mm.
Of the plurality of protrusions, the protrusion 13 is a hollow rectangular parallelepiped having a height of 5 mm, a width of 10 mm, and a length of 10 mm (the hollow portion is connected to the cavity of the box-shaped portion), and the protrusion 12 is provided. It is provided on a side surface (30 mm × 80 mm, surface B) adjacent to the side surface A. The protrusion 13 has a thin wall and a roof (a wall thickness of 1 mm on four surfaces extending in the vertical direction from the surface B and a wall thickness of 0.5 mm on the roof).
Of the plurality of protrusions, the protrusion 14 is provided on a side surface (80 mm × 25 mm, surface A') facing the side surface on which the protrusion 12 is provided. In the plan view of this side surface, protrusions having a length of 7 mm and a thickness of 1 mm parallel to the short side direction and a height of 4 mm in the vertical direction from this side surface are provided at intervals of 10 mm, and two of them are provided. As a wall, it has a square tubular structure having a thin surface (roof) with a thickness of 0.7 mm in which the ends of these two walls are connected in a roof shape.
The gate of the mold for forming the simulated parts is on the side of surface A'opposite to the surface B, the gate outlet is 6 mm x 1.5 mm, and the mold runner and spool are T-shaped runners. Gates are arranged at both ends and two molded parts are arranged. The size of the runner is 4 mm in diameter and 35 mm in length, and the size of the spool is 130 mm in length and the diameter increases toward the downstream side. The downstream side (runner side) has a diameter of 7 mm, and the upstream side has a diameter of 3 mm.
The shape of the molded body, including the thin part where the thickness was described, could be molded to the desired size without any problem, and the one with no material breakage on the spool and runner was marked as 〇, and the shape of the molded body could be molded without problems. The case where the material was broken at the spool and the runner was marked with Δ, and the case where the thin part of the molded body could not be molded to the designed shape size was marked with ×.

[Moldability 2]
Using a composite material, an end member (FIGS. 3A and 3B) having a thin wall thickness of 0.9 mm, a wall thickness of 0.4 mm, and a wall thickness of 0.2 mm for a corrugated pipe is injected. It was molded by molding, and the moldability of the molded product was evaluated.
The molding conditions of each Example and each Comparative Example were the same. Specifically, the molding conditions were a cylinder temperature of 200 ° C., a mold temperature of 40 ° C., and an injection speed of 150 mm / sec.
Specifically, the end member for the corrugated pipe has a hollow cylindrical portion 21 and a small diameter portion connected to one end of the cylindrical portion 21 in the length direction at the same diameter as the cylindrical portion 21. It has a hollow cylindrical enlarged diameter portion 22 that spreads like a trumpet. The cylindrical portion 21 has an inner diameter of 25.5 mm and a thickness of 1.5 mm, and the enlarged diameter portion 22 has an outer diameter of an end portion (maximum diameter portion) of 50 mm and a thickness of 1.2 mm. The total length of the columnar portion 21 and the enlarged diameter portion 22 is 40 mm. Further, inside the boundary between the columnar portion 21 and the enlarged diameter portion 22, a disk-shaped lid portion 23 is provided so as to close the hollow of the columnar portion 21, and the lid portion 23 has a width at a position connected to the columnar portion 21. It has a thickness of 0.4 mm and a particularly thin portion 24 over the entire circumference at 1 mm, and the thickness of the central portion of the lid portion 23 excluding this portion is as thin as 0.9 mm. The lid portion 23 further has a columnar protrusion 25 having a diameter of 3 mm from the circumference of the side surface of the enlarged diameter portion 22 of the lid portion 23 and a height of 14 mm from the lid portion 23, and the outer peripheral portion of the rising portion of the protrusion 25. The lid portion 23 has an extremely thin portion 26 having a width of 1 mm and a thickness of 0.2 mm. Further, the lid portion 23 has a protrusion 27 having a length of 10 mm, a width of 1 mm, and a height of 10 mm from the lid portion 23 at the center of the side surface of the enlarged diameter portion 22 of the lid portion 23. Further, the outer periphery of the side surface of the cylindrical portion 21 has a spiral mountain protrusion, that is, a portion that can be fitted by screwing into the inner surface of the corrugated pipe (spiral corrugated pipe).
The gate of the mold for forming the end member is located at the end of the enlarged diameter portion 22, the gate outlet is 6 mm × 1.5 mm, and the mold runner and spool are arranged at both ends of the T-shaped runner. The size of the runner is 4 mm in diameter and 35 mm in length, and the size of the spool is 130 mm in length and the diameter increases toward the downstream side, and the size of the spool is on the downstream side (runner side). ) Is 7 mm in diameter, and the upstream side is 3 mm in diameter.
The shape of the molded body, including the thin-walled part, can be molded without problems such as forming holes in the desired size, and those without material breakage on the spool and runner are marked as 〇, and holes are formed in the thin-walled part of the molded body. Those having a problem in molding of the above were marked with x.

[Moldability 3]
Using a composite material, a joint member for pipes (FIG. 4) having a male screw structure 33 on the joint surfaces 32 provided on both sides of the semi-cylindrical structure 31 was formed by injection molding. This joint member has a portion having a wall thickness of 1 mm or less in the male screw structure portion. The moldability when this molded product was molded was evaluated.
The molding conditions of each Example and each Comparative Example were the same. Specifically, the molding conditions were a cylinder temperature of 200 ° C., a mold temperature of 40 ° C., and an injection speed of 150 mm / sec.
Specifically, the shape of the joint member is a joint surface 32 for joining the semi-cylindrical structures 31 to each other on both sides of the semi-cylindrical structure 31 in which a spiral groove for joining the corrugated pipe is formed on the inner surface. The male screw structure 33 is provided at the four corners of the joint surface 32. This joint member has a rectangular shape (width 60 mm × length 85 mm) in a plan view, and a semi-cylindrical structure 31 obtained by dividing a cylinder having an outer diameter of 50 mm and a wall thickness of 3 mm in half is formed at the center in the length direction. It is provided over the entire width direction (60 mm). The four corners of the plan view rectangle have a male screw structure 33. The size of the male screw structure 33 is a maximum diameter of 9.2 mm, a minimum diameter of 8 mm, a pitch of 1.2 mm, and a length of 16 mm (height from the joint surface), respectively. The male thread structure 33 has a thickness of 1 mm or less in the vicinity of the tip of the thread and a thickness reduction structure toward the tip of the thread.
The gate of the mold for forming the contact member is on the side surface in the length direction, the gate outlet is 6 mm × 1.5 mm, and the mold runner and the spool are two with gates arranged at both ends of the T-shaped runner. The size of the runner is 4 mm in diameter and 35 mm in length, and the size of the spool is 130 mm in length and has an enlarged diameter toward the downstream side, and the downstream side (runner side) has a diameter. It is 7 mm and the upstream side has a diameter of 3 mm.
The shape of the molded body including the male screw structure can be molded to the desired size without any problem, and the one with no material breakage at the spool and runner is marked as 〇, and the shape of the molded body can be molded without problems, but the material at the spool and runner. Those that sometimes broke were marked with Δ, and those having problems in molding the molded body (molding including the male screw structure) were marked with x.

[Test Example 1]
In Test Example 1, a composite material was prepared using a low-density polyethylene resin and an ethylene-acrylic acid copolymer resin as the resin and pulp as the cellulose material. Details will be described with reference to Examples 1 and 2 and Comparative Examples 1 and 2 below.

(Examples 1 and 2)
In Examples 1 and 2, low-density polyethylene 1 (LDPE1: Novatec LC600A (trade name), manufactured by Japan Polyethylene Corporation), ethylene-acrylic acid copolymer 1 (EAA1: Nuclel (trade name), Mitsui-Dupont). (Manufactured by Polychemical Co., Ltd.) and pulp 1 or 2 were mixed at the blending ratio shown in the upper part of Table 1 and melt-kneaded using a kneader to obtain a composite material. In the melt-kneading, 20 parts by mass of water was first added to 100 parts by mass of the total of the resin and the cellulose fibers, and then 20 parts by mass of water was added during the kneading. In this way, the cellulose fiber-dispersed resin composite materials of Examples 1 and 2 having different types of pulp were obtained.
The composite material thus obtained was subjected to injection molding as described in Moldability 1 to 3 to obtain a molded product having a thin-walled portion according to Example 1.
Further, also in each of the following Examples and Comparative Examples, a molded product having a thin wall portion was obtained by performing the above injection molding on the obtained composite material.

(Comparative Examples 1 and 2)
Low-density polyethylene 1 (Novatec LC600A (trade name), manufactured by Japan Polyethylene Corporation), ethylene-acrylic acid copolymer 1 (Nucrel (trade name), manufactured by Mitsui-Dupont Polychemical), and pulp 1 or 2 Was mixed at the blending ratio shown in the upper part of Table 1 and melt-kneaded using a kneader to obtain a composite material. In this way, the cellulose fiber-dispersed resin composite materials of Comparative Examples 1 and 2 having different types of pulp were produced.

The content of cellulose fibers in each composite material is shown in the middle of Table 1, and the evaluation results and the like are shown in the bottom of Table 1.
Regarding the presence or absence of agglomerates 1, 1b and 1c, the obtained composite material and low-density polyethylene 1 were mixed at a mass ratio of composite material: low-density polyethylene 1 = 6: 44 to prepare the composite material with a resin. It was diluted and evaluated on a sheet obtained using this. The content of cellulose fibers in the diluted sheet was 3.5 to 4.2% by mass. The area of 7 mm in length × 8 mm in width of the sheet was set as one place, and five places were randomly set as the observation area.
The ratio of the total area of the agglomerates having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ² (area range r1) to the observed area is defined as s1, and the area occupied by the observed area is Table 1 shows the ratio of the total area of the agglomerates of 1.0 × 10 ^{3 to} 1.0 × 10 ⁶ μm ² (area range r2) as s2. Table 1 also shows the ratio of s1 to s2. Further, FIG. 1 shows the distribution of the area of agglomerates in the composite material of Example 1.
In the table below, (s1 / s2) × 100 means “1.0 × 10 ^{3 to} 1.0 × 10 ⁶ among the aggregates of cellulose fibers contained in the cellulose fiber dispersed resin composite material in a plan view. occupying the sum of the areas of the aggregate area of [mu] m ^2, it means the proportion "of the sum of the areas of ^{3.0 × 10 4 ~1.3 × 10 5} μm aggregates ² area.

In the composite materials of Examples 1 and 2, aggregates of cellulose fibers having an area specified in the present invention were formed, whereas in the composite materials of Comparative Examples 1 and 2, the area was 2.0 × 10 ⁴ to 2. No 1.0 × 10 ⁵ μm ² agglomerates were observed. Comparing Examples 1 and 2 with those containing the same pulp as Comparative Examples 1 and 2, it can be seen that the composite materials of Examples 1 and 2 have high impact strength. It can also be seen that the composite materials of Examples 1 and 2 have a high MFR value and are excellent in fluidity during molding.
Further, looking at the composite materials of Examples 1 and 2 having the above-mentioned agglomerates of a specific size, it can be seen that the one having a large ratio of s1 to s2 has a particularly high impact strength. The impact strength of this composite material is an index of the impact strength of the molded product obtained by molding the composite material.
The composite material of Examples 1 and 2 has a cellulose fiber having a fiber length of 0.3 mm or more, a cellulose fiber having a fiber length of 0.8 mm or more, and a length-weighted average fiber length of 0.3 mm or more. It was a thing.
The molded article using Examples 1 and 2 having the agglomerates 1 but not the agglomerates 2 was excellent in moldability. The molded product using the composite material of Comparative Examples 1 and 2 having no agglomerate 1 had a defect in the thin-walled portion and was inferior in moldability.

[Test Example 2]
In Test Example 2, a composite material was prepared using a waste paper of laminated paper and a low-density polyethylene resin. Details will be described with reference to Examples 3 to 5 below.

(Examples 3 and 4)
Waste paper of polyethylene laminated paper (having paper, polyethylene thin layer and aluminum thin layer) is crushed using a rotary blade type crusher (manufactured by Horai) and low density polyethylene 1 (LDPE1: Novatec). LC600A (trade name) and Nippon Polyethylene Corporation) were mixed at the blending ratio shown in the upper part of Table 2. When crushing the waste paper of the polyethylene-laminated paper, two types of mesh pore diameters of the crusher shown in the upper part of Table 2 were used. This mixture was put into a kneader and melt-kneaded. In the melt kneading, 20 parts by mass of water was first added to 100 parts by mass of the total of the resin and the cellulose fiber, and 20 parts by mass of water was further added during the kneading. In this way, the cellulose fiber-dispersed resin composite materials of Examples 3 and 4 were obtained.

(Example 5)
Waste paper of polyethylene laminated paper (having paper, polyethylene thin layer and aluminum thin layer) is crushed using a rotary blade type crusher (manufactured by Horai) and low density polyethylene 1 (LDPE1: Novatec). LC600A (trade name) and Nippon Polyethylene Corporation) were mixed at the blending ratio shown in the upper part of Table 2 without adding water. When crushing the waste paper of the polyethylene-laminated paper, the mesh pore diameter of the crusher shown in the upper part of Table 2 was used. This mixture was put into a kneader and melt-kneaded. In this way, a cellulose fiber-dispersed resin composite material (Example 5) was produced.

The content of cellulose fibers in each composite material is shown in the middle of Table 2, and the evaluation results and the like are shown in the bottom of Table 2.
Regarding the presence or absence of agglomerates 1, 1b and 1c, the obtained composite material and low-density polyethylene 1 were mixed at a mass ratio of composite material: low-density polyethylene 1 = 8:42, so that the composite material was made of resin. It was diluted and the sheet obtained using this was used. The amount of cellulose fibers in the sheet obtained by dilution was 3.1% by mass. The area of 7 mm in length × 8 mm in width of the sheet was set as one place, and five places were randomly set as the observation area.
Aluminum derived from waste paper is also observed in a dark color in transmitted light, but in transmitted light, the aggregates of cellulose fibers have higher brightness than aluminum, so that the aggregates of cellulose fibers can be discriminated.
The ratio of the total area of the agglomerates having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ² (area range r1) to the observed area is defined as s1, and the area occupied by the observed area is Table 2 shows the ratio of the total area of the agglomerates of 1.0 × 10 ^{3 to} 1.0 × 10 ⁶ μm ² (area range r2) as s2. Table 2 also shows the ratio of s1 to s2.

All of the molded products using the composite materials of Examples 3 to 5 were excellent in impact strength. In the molded product using the composite material of Examples 3 and 4 having no agglomerate 2, the impact strength was more excellent. Further, in the molded product using the composite material of Example 5, during injection molding, the material tends to be cut off by the runner and the spool and the material remains on the molding machine side, whereas the molded product of Examples 3 and 4 The molded product using the composite material of No. 1 did not cause such a problem and was excellent in moldability. Further, regarding the composite material of Example 4, in addition to the moldability 1, the wall thickness of the protrusion 12 of the simulated part used for the evaluation of the moldability 1 was set to 0.05 mm with a wall thickness of 1 mm. When the moldability was evaluated in the same manner as in the moldability 1 with the simulated parts having the same moldability 1, holes were formed in the protrusions 12 and the moldability was poor.

[Test Example 3]
In Test Example 3, a composite material was produced using various materials. Details will be described below as Examples 6 to 11 and Reference Example 1.

(Examples 6, 8 to 10)
Each material was mixed at the compounding ratio shown in the upper part of Table 3. The waste paper of the polyethylene-laminated paper was crushed in advance and used, and when crushing, the pore diameter of the mesh of the crusher was shown in the upper part of Table 3. This mixture was put into a kneader and melt-kneaded. In the melt kneading, 20 parts by mass of water was first added to 100 parts by mass of the total of the resin and the cellulose fiber, and 20 parts by mass of water was further added during the kneading. In this way, the cellulose fiber-dispersed resin composite materials of Examples 6 and 8 to 10 were obtained.

LDPE1: Low density polyethylene (manufactured by Japan Polyethylene Corporation, Novatec LC600A (trade name))
HDPE1: High-density polyethylene (manufactured by Japan Polyethylene Corporation, Novatec HJ490 (trade name))
EVA1: Ethylene-vinyl acetate copolymer acid-modified PE1: Maleic acid-modified polyethylene (DuPont, Fusabond (trade name))
CB-MB1: Carbon black masterbatch (base resin; polyethylene)

(Example 11)
The mixture was mixed at the compounding ratio shown in the upper part of Table 3. The waste paper of the polyethylene-laminated paper was crushed in advance and used, and when crushing, the pore diameter of the mesh of the crusher was shown in the upper part of Table 3. This mixture was put into a kneader and melt-kneaded. No water was added during melt kneading.

(Reference example 1)
HDPE1 shown in the upper part of Table 3 was used as it was.

(Example 7)
A polyethylene fiber aluminum-attached polyethylene thin film piece (cellulose / aluminum-attached PE thin film piece) is removed by peeling off the paper part with a pulper from the collected material of a beverage container made of paper, a polyethylene thin film layer and a polyethylene laminated paper having an aluminum thin film layer. Obtained. The thin film pieces, the number cm ² 100 cm ² about various shapes, are cut into pieces of size, it was wetted by being immersed in water at stripping step of the paper portion (water content 30%). The polyethylene constituting this cellulose-aluminum-attached PE thin film piece is low-density polyethylene. Next, the cellulose / aluminum-attached PE thin film piece and other materials were added to the kneader at the blending ratio (mass part based on the dry mass) shown in the upper part of Table 3, melt-kneaded, and the resin composite material (moisture content 1% by mass). The following) was obtained. In the melt kneading, 20 parts by mass of water was added to 100 parts by mass of the total of the resin and the cellulose fiber during the kneading.

The content of cellulose fibers in each composite material is shown in the middle of Table 3, and the evaluation results and the like are shown in the bottom of Table 3.
For the agglutinin 1, the obtained composite material was diluted with a resin, and the result was performed on a sheet obtained using the same. Low-density polyethylene was used in Examples 6 to 9 and high-density polyethylene was used in Examples 10 and 11 as the diluted resin, and the amount of cellulose fibers in the sheet obtained by dilution was 3.5 to 4.5 mass. It was made to be%. The area of 7 mm in length × 8 mm in width of the sheet was set as one place, and five places were randomly set as the observation area.

All of the molded products using the composite material of the examples were excellent in impact strength. Further, comparing both Examples 10 and 11 in which the same material is used, in the molded product using the composite material of Example 11, the material is cut by the runner and the spool during injection molding, and the material is separated. While there is a tendency for the composite material to remain on the molding machine side, the composite material of Example 10 having no agglomerates 2 does not cause such a problem and is excellent in moldability.

Claims (18)

A resin molded product obtained by molding a cellulose fiber-dispersed resin composite material in which cellulose fibers are dispersed in a thermoplastic resin.
The resin molded body has a wall thickness of 0.1 mm or more.
The cellulose fiber-dispersed resin composite contains agglomerates of the cellulose fibers, and at least a part of the agglomerates has an area of 2.0 × 10 ^{4 to} 2.0 × 10 ⁵ μm ^{2 in} a plan view. A resin molded body that is an agglomerate. Claimed that at least a part of the cellulose fiber agglomerates contained in the cellulose fiber-dispersed resin composite material is an agglomerate having an area of 3.0 × 10 ^{4 to} 1.3 × 10 ⁵ μm ^{2 in} a plan view. The resin molded product according to 1. The agglomerates of the cellulose fibers contained in the cellulose fiber dispersion resin in the composite is a aggregate of 1.0 × 10 ⁷ [mu] m ² of less than an area in a plan view, a resin molded body according to claim 1 or 2. The resin molded product according to any one of claims 1 to 3, which has at least a portion having a wall thickness of 1 mm or less. The resin molded product according to any one of claims 1 to 4, which contains a cellulose fiber having a fiber length of 0.3 mm or more. The resin molded product according to any one of claims 1 to 5, which contains a cellulose fiber having a fiber length of 0.8 mm or more. The resin molded product according to any one of claims 1 to 6, wherein the content of the cellulose fiber determined by the following measurement method in the cellulose fiber-dispersed resin composite material is 1% by mass or more and less than 70% by mass. ..
<Measurement method>
A sample of the cellulose fiber-dispersed resin composite material is subjected to thermogravimetric analysis (TGA) at a heating rate of + 10 ° C./min under a nitrogen atmosphere, and the content of the cellulose fiber is calculated by the following [Equation 1].
[Formula 1] (Cellulose fiber content [mass%]) = (mass reduction of sample between 200 and 380 ° C. [mg]) x 100 / (mass [mg] of sample before thermogravimetric analysis ) The resin molded product according to any one of claims 1 to 7, wherein the content of the cellulose fibers in the cellulose fiber-dispersed resin composite material is 5% by mass or more and less than 50% by mass. The thermoplastic resins are polyolefin resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin, polyamide resin, polyvinyl chloride resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polystyrene resin, and 3-. The resin molded product according to any one of claims 1 to 8, which is any one or more of the hydroxybutyrate-co-3-hydroxyhexanoate polymer resins. The resin molded product according to any one of claims 1 to 9, wherein the thermoplastic resin is a polyolefin resin. The resin molded product according to any one of claims 1 to 10, which comprises aluminum. The resin molded product according to claim 10, wherein the polyolefin resin contains one or more of a low-density polyethylene resin, a high-density polyethylene resin, and a polypropylene resin. The one according to any one of claims 1 to 11, wherein the composite material is a polyolefin resin composition containing any one or more of carbon black, a light stabilizer, and an inorganic powder having a refractive index of 2 or more. Resin molded body. The resin molded product according to any one of claims 1 to 13, wherein the resin molded product is a product having a cyclic structure or a multi-divided product having a ring structure. The resin molded body according to any one of claims 1 to 14, wherein the resin molded body is a joint member or an end member for a corrugated tube having a wavy shape in the longitudinal direction. The molded product according to any one of claims 1 to 15, wherein the resin molded product is an injection molded product. The resin molded product according to any one of claims 1 to 16, wherein at least a part of the constituent material is derived from a recycled material. The resin molded product according to any one of claims 1 to 17, which is a member for civil engineering, building materials, or automobiles.

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