WO2019171611A1

WO2019171611A1 - Resin composition and resin molded article

Info

Publication number: WO2019171611A1
Application number: PCT/JP2018/026780
Authority: WO
Inventors: 八百　健二; 涼田中; 佳奈宮崎; 正洋森山
Original assignee: 富士ゼロックス株式会社
Priority date: 2018-03-06
Filing date: 2018-07-17
Publication date: 2019-09-12
Also published as: JP2019151788A

Abstract

A resin composition comprising at least one cellulose acylate selected from cellulose acetate propionate and cellulose acetate butyrate, a polyhydroxyalkanoate comprising poly(lactic acid) and a poly(hydroxycarboxylic acid) other than the poly(lactic acid), and an ester compound having a molecular weight of 250 to 2000 inclusive, wherein the ratio of the mass of the poly(lactic acid) to the mass of the cellulose acylate is 0.05 to 0.5 inclusive, the ratio of the mass of the poly(hydroxycarboxylic acid) other than the poly(lactic acid) to the mass of the cellulose acylate is 0.02 to 0.2 inclusive, and the ratio of the mass of the ester compound to the mass of the cellulose acylate is 0.05 to 0.15 inclusive.

Description

Resin composition and resin molded body

The present invention relates to a resin composition and a resin molded body.

Conventionally, various resin compositions have been provided and used for various applications. Resin compositions are particularly used in home appliances, various parts of automobiles, casings, and the like. Thermoplastic resins are also used in parts such as office equipment and electronic electrical equipment casings.
In recent years, plant-derived resins have been used, and cellulose derivatives are one of the conventionally known plant-derived resins.

For example, Patent Document 1 discloses “a resin composition containing a cellulose ester resin, a compound containing an adipic acid ester, and a polyhydroxyalkanoate resin.”

Japanese Unexamined Patent Publication No. 2016-069423

A resin molded body formed from a resin composition containing cellulose acylate containing at least one selected from cellulose acetate propionate and cellulose acetate butyrate, polylactic acid, and an ester compound having a molecular weight of 250 to 2000 is In some cases, the temperature was low and the film was easily deformed by heat. Further, even when poly (hydroxycarboxylic acid) other than polylactic acid is included, the deflection temperature under load is low, and it may be easily deformed by heat.

Cellulose acylate containing at least one selected from cellulose acetate propionate and cellulose acetate butyrate, polyhydroxyalkanoate containing polylactic acid and poly (hydroxycarboxylic acid) other than polylactic acid, and molecular weight of 250 to 2000 In the resin composition containing an ester compound, the ratio of the mass of polylactic acid to the mass of cellulose acylate is less than 0.05 or more than 0.5, and the mass of poly (hydroxycarboxylic acid) other than polylactic acid relative to the mass of cellulose acylate Is less than 0.02 or more than 0.2, or the ratio of the mass of the ester compound having a molecular weight of 250 to 2000 with respect to the mass of cellulose acylate is less than 0.05 or more than 0.15, or the deflection temperature under load And crack resistance test Definitive product of the drop height of the hard ball as compared to if it is less than 80, while maintaining the crack resistance, and to provide a resin composition which resin molding thermal deformation is suppressed is obtained.

The above problem can be solved by the following means.

<1>
A first aspect of the present invention is a cellulose acylate comprising at least one selected from cellulose acetate propionate and cellulose acetate butyrate;
A polyhydroxyalkanoate containing polylactic acid and a poly (hydroxycarboxylic acid) other than the polylactic acid;
An ester compound having a molecular weight of 250 to 2000,
Including
The ratio ((B) / (A)) of the mass (B) of the polylactic acid to the mass (A) of the cellulose acylate is 0.05 or more and 0.5 or less, and the mass (A) of the cellulose acylate The ratio ((C) / (A)) of the mass (C) of the poly (hydroxycarboxylic acid) other than the polylactic acid to 0.02 or more and 0.2 or less, and the mass (A) of the cellulose acylate It is a resin composition whose ratio ((D) / (A)) of the mass (D) of the ester compound is 0.05 or more and 0.15 or less.
<2>
In the resin composition according to <1>, the product of the deflection temperature under load and the drop height of the hard ball in the crack resistance test may be 80 or more.
<3>
Another aspect of the present invention is a cellulose acylate comprising at least one selected from cellulose acetate propionate and cellulose acetate butyrate;
A polyhydroxyalkanoate containing polylactic acid and a poly (hydroxycarboxylic acid) other than the polylactic acid;
An ester compound having a molecular weight of 250 to 2000,
Including
It is a resin composition in which the product of the deflection temperature under load and the drop height of the hard ball in the crack resistance test is 80 or more.

<4>
In the resin composition according to any one of <1> to <3>, the ester compound may be a fatty acid ester compound.
<5>
In the resin composition according to <4>, the fatty acid ester compound may be a compound containing an adipic acid ester.

<6>
The resin composition according to any one of <1> to <5> further includes a core-shell structure polymer having a core layer and a shell layer containing a (meth) acrylic polymer on the surface of the core layer, The ratio ((E) / (A)) of the polymer (E) of the core-shell structure to the mass (A) of the cellulose acylate may be 0.01 or more and 0.2 or less.
<7>
<6> The resin composition according to <6>, wherein the core layer of the core-shell structure polymer includes a (meth) acrylic polymer of (meth) acrylic acid alkyl ester having an alkyl chain having 1 to 8 carbon atoms. Good.
<8>
<6> In the resin composition according to <6>, the shell layer of the polymer having the core-shell structure may include a copolymer of two or more (meth) acrylic acid alkyl esters having different alkyl chain carbon numbers.

<9>
The resin composition according to any one of <1> to <8> may further contain a (meth) acrylic polymer in the matrix.
<10>
<9> The resin composition according to <9>, wherein the (meth) acrylic polymer in the matrix is a polymer having a structural unit derived from a (meth) acrylic acid alkyl ester, and the mass of the cellulose acylate (A ) The ratio ((F) / (A)) of the mass (F) of the polymer having a structural unit derived from the (meth) acrylic acid alkyl ester may be 0.01 or more and 0.1 or less.
<11>
In the resin composition according to <9> or <10>, the weight average molecular weight of the (meth) acrylic polymer in the matrix may be 30000 or less.

<12>
Another embodiment of the present invention is a resin molded article comprising the resin composition according to any one of <1> to <11>.
<13>
The resin molded body described in <12> may be an injection molded body.

According to <1>, the cellulose acylate containing at least one selected from cellulose acetate propionate and cellulose acetate butyrate, polylactic acid and polyhydroxyalkano containing poly (hydroxycarboxylic acid) other than polylactic acid And a resin composition comprising an ester compound having a molecular weight of 250 or more and 2000 or less, wherein the ratio of the mass of polylactic acid to the mass of cellulose acylate is less than 0.05 or more than 0.5, other than polylactic acid relative to the mass of cellulose acylate When the ratio of the mass of the poly (hydroxycarboxylic acid) is less than 0.02 or more than 0.2, or the ratio of the mass of the specific ester compound to the mass of the cellulose acylate is less than 0.05 or more than 0.15 Compared to ensuring crack resistance, thermal deformation is suppressed The resin composition in which the resin molded article is obtained is provided.

According to <2> or <3>, cellulose acylate containing at least one selected from cellulose acetate propionate and cellulose acetate butyrate, polylactic acid, and poly (hydroxycarboxylic acid) other than polylactic acid In the resin composition containing the polyhydroxyalkanoate contained and the ester compound having a molecular weight of 250 or more and 2000 or less, compared to the case where the product of the deflection temperature under load and the drop height of the hard ball in the crack resistance test is less than 80, the crack resistance There is provided a resin composition from which a resin molded body in which thermal deformation is suppressed while securing the above.

According to the aspect of <4> and <5>, the ratio of the mass of polylactic acid to the mass of cellulose acylate is less than 0.05 or more than 0.5, and poly (hydroxycarboxylic) other than polylactic acid relative to the mass of cellulose acylate When the ratio of the mass of the acid) is less than 0.02 or more than 0.2, or the ratio of the mass of the ester compound having a molecular weight of 250 to 2000 with respect to the mass of the cellulose acylate is less than 0.05 or more than 0.15, Or, compared with the case where the product of the deflection temperature under load and the drop height of the hard ball in the crack resistance test is less than 80, the ester compound having a molecular weight of 250 or more and 2000 or less is a fatty acid ester, and heat deformation while ensuring crack resistance. There is provided a resin composition from which a resin molded product in which the suppression is suppressed can be obtained.

<6>, <7>, <8> According to the aspect of <8>, the ratio of the mass of polylactic acid to the mass of cellulose acylate is less than 0.05 or more than 0.5, other than polylactic acid to the mass of cellulose acylate When the ratio of the mass of poly (hydroxycarboxylic acid) is less than 0.02 or more than 0.2, or the ratio of the mass of the specific ester compound to the mass of cellulose acylate is less than 0.05 or more than 0.15, or Compared with the case where the product of the deflection temperature under load and the drop height of the hard ball in the crack resistance test is less than 80, the core-shell structure having a core layer and a shell layer containing a (meth) acrylic polymer on the surface of the core layer. Provided is a resin composition that includes a polymer, and that can provide a resin molded body that can prevent cracking while ensuring crack resistance.

According to <9>, <10>, and <11>, the cellulose acylate, polylactic acid, and polylactic acid, wherein the resin composition includes at least one selected from cellulose acetate propionate and cellulose acetate butyrate Compared with the case where only poly (hydroxycarboxylic acid) other than the above and an ester compound having a molecular weight of 250 or more and 2000 or less are contained, a resin molded product in which thermal deformation is suppressed is provided.

According to <12> and <13>, cellulose acylate containing at least one selected from cellulose acetate propionate and cellulose acetate butyrate, polylactic acid and poly (hydroxycarboxylic acid) other than polylactic acid In the resin molded product containing the polyhydroxyalkanoate and the ester compound having a molecular weight of 250 or more and 2000 or less, the ratio of the mass of polylactic acid to the mass of cellulose acylate is less than 0.05 or more than 0.5, and the mass of cellulose acylate The ratio of the mass of the poly (hydroxycarboxylic acid) other than polylactic acid to less than 0.02 or more than 0.2, or the ratio of the mass of the ester compound having a molecular weight of 250 to 2000 with respect to the mass of the cellulose acylate is less than 0.05 Or more than 0.15 Or, compared with the case where the product of the deflection temperature under load and the drop height of the hard sphere in the crack resistance test is less than 80, a resin composition from which a resin molded body is obtained in which thermal deformation is suppressed while ensuring crack resistance. Provided.

Hereinafter, an embodiment which is an example of a resin composition and a resin molded body of the present invention (in this specification, matters common to the first embodiment and the second embodiment are referred to as “this embodiment”. ).

<Resin composition>
The resin composition according to the first embodiment is a cellulose acylate containing at least one selected from cellulose acetate propionate and cellulose acetate butyrate (hereinafter sometimes referred to as “specific cellulose acylate”). A polyhydroxyalkanoate containing polylactic acid and poly (hydroxycarboxylic acid) other than the polylactic acid, and an ester compound having a molecular weight of 250 or more and 2000 or less (hereinafter sometimes referred to as “specific ester compound”).
And ratio ((B) / (A)) of the mass (B) of the said polylactic acid with respect to the mass (A) of the said cellulose acylate is 0.05-0.5. Further, the ratio ((C) / (A)) of the mass (C) of the poly (hydroxycarboxylic acid) other than the polylactic acid to the mass (A) of the cellulose acylate is 0.02 or more and 0.2 or less. . Furthermore, the ratio ((D) / (A)) of the mass (D) of the ester compound to the mass (A) of the cellulose acylate is 0.05 or more and 0.15 or less.

The resin composition according to the second embodiment includes cellulose acylate containing at least one selected from cellulose acetate propionate and cellulose acetate butyrate, polylactic acid, and poly (hydroxycarboxylic acid) other than polylactic acid. A polyhydroxyalkanoate containing, and an ester compound having a molecular weight of 250 or more and 2000 or less.
The product of the deflection temperature under load (° C.) and the drop height (m) of the hard ball in the crack resistance test is 80 or more.

Conventionally, cellulose acylate (acylated cellulose derivative) in which a part of the hydroxyl group is substituted with an acyl group is a non-edible resource and is a primary derivative that does not require chemical polymerization, and is therefore an environmentally friendly resin material. . Among cellulose acylates, cellulose acetate propionate and cellulose acetate butyrate (specific cellulose acylate) are materials having excellent transparency.

Depending on the high transparency of the specific cellulose acylate, there are cases where the specific cellulose acylate is developed for uses that are transparent and require crack resistance. In this case, the crack resistance of the resin molding is improved by using a resin composition in which polylactic acid and a specific ester compound are mixed with the specific cellulose acylate. However, the resin molded body formed from this resin composition has a low deflection temperature under load and may be easily thermally deformed.

In contrast, in the resin composition according to the present embodiment, poly (hydroxycarboxylic acid) other than polylactic acid is further added to the mixture of specific cellulose acylate, polylactic acid, and specific ester compound. The deflection temperature under load of the poly (hydroxycarboxylic acid) itself other than polylactic acid is lower than the deflection temperature under load of the mixture of the specific cellulose acylate, polylactic acid, and the specific ester compound. Nevertheless, the resin composition according to the present embodiment can provide a resin molded body that can prevent cracking while ensuring crack resistance. The reason for this is not clear, but is presumed as follows.

When the specific cellulose acylate, polylactic acid, and the specific ester compound are mixed, the specific ester compound is selectively dissolved in the phase of the specific cellulose acylate due to the difference in affinity. The resin composition in this state has a specific cellulose acylate phase containing a specific ester compound and a polylactic acid phase, and an interface is formed between both phases. And since the fracture at the interface between the two phases becomes dominant, it is considered that the deflection temperature under load is lowered.

Poly (hydroxycarboxylic acid) other than polylactic acid has the same degree of affinity as both specific cellulose acylate containing a specific ester compound and polylactic acid. Therefore, when poly (hydroxycarboxylic acid) other than polylactic acid is further mixed with the mixture of specific cellulose acylate, polylactic acid, and specific ester compound, poly (hydroxycarboxylic acid) other than polylactic acid becomes the specific ester compound. By compatibilizing the phase of the specific cellulose acylate contained and the phase of polylactic acid and binding the interfaces of both phases, the breakage at the interfaces of both phases is suppressed. Therefore, it is considered that crack resistance is ensured and a decrease in the deflection temperature under load is suppressed. Moreover, it is thought that crystallization of poly (hydroxycarboxylic acid) other than polylactic acid is accelerated | stimulated because poly (hydroxycarboxylic acid) other than polylactic acid exists in the interface of both phases. Therefore, it is considered that due to crystallization of poly (hydroxycarboxylic acid) other than polylactic acid, crack resistance is ensured and a decrease in deflection temperature under load is suppressed. That is, it is considered that the above-described action can provide a resin molded body that can ensure crack resistance and suppress thermal deformation.

Also, it has been found that the above-mentioned action may not be easily achieved by simply mixing poly (hydroxycarboxylic acid) other than polylactic acid. Furthermore, even when only the ratio of poly (hydroxycarboxylic acid) other than polylactic acid to the specific cellulose acylate was examined, it was found that the above-mentioned action may be difficult to express. Therefore, in 1st Embodiment, resin molding is carried out by making mass ratio of each component (polylactic acid, specific ester compound, and poly (hydroxycarboxylic acid) other than polylactic acid) with respect to specific cellulose acylate into the above-mentioned range. It is considered that the crack resistance of the body is ensured and thermal deformation is suppressed. Since the mass ratio of each component with respect to the specific cellulose acylate is in the above-described range, it is presumed that the above-described effect is exhibited because it is in a balance that exerts each role of each component.

In addition, the resin composition according to the second embodiment provides a resin molded body in which the product of the deflection temperature under load (° C.) and the steel ball height (m) in the crack resistance test is 80 or more. When this numerical value is 80 or more, the resin molded body has a characteristic that resistance to cracking is ensured and heat deformation is difficult. As described above, the poly (hydroxycarboxylic acid) other than polylactic acid is present at the interface between the phase of the specific cellulose acylate containing the specific ester compound and the phase of the polylactic acid, so that the above-described effect is exhibited. Presumed to be.

From the above, it is presumed that the resin molded body according to the present embodiment ensures crack resistance and suppresses a decrease in the deflection temperature under load.

Hereinafter, the components of the resin composition according to the present embodiment will be described in detail.

In the present specification, “(meth) acryl” means that both “acryl” and “methacryl” are included. “(Meth) acrylate” means that both “acrylate” and “methacrylate” are included.

[Specific cellulose acylate]
In the resin composition according to the present embodiment, the specific cellulose acylate includes at least one selected from cellulose acetate propionate and cellulose acetate butyrate. That is, either cellulose acetate propionate or cellulose acetate butyrate may be contained, and both cellulose acetate propionate and cellulose acetate butyrate may be used in combination.

Cellulose acetate propionate is a cellulose derivative in which a part of the hydroxyl group is substituted with an acetyl group and a propionyl group. Cellulose acetate butyrate is a cellulose derivative in which a part of the hydroxyl group is substituted with an acetyl group and a butyl group. The specific cellulose acylate is specifically a cellulose derivative represented by the following general formula (1).

In General Formula (1), R ¹ , R ² , and R ³ each independently represent a hydrogen atom or an acyl group (acetyl group and propionyl group, or acetyl group and butyryl group). n represents an integer of 2 or more. However, at least a part of n R ¹ , n R ² , and n R ³ represents an acyl group, and in the case of cellulose acetate propionate, the acyl group represents an acetyl group and a propionyl group. . In the case of cellulose acetate butyrate, the acyl group represents an acetyl group and a butyryl group.

In the general formula (1), the range of n is not particularly limited, and examples thereof include 200 or more and 1000 or less. The range of n may be 500 or more and 1000 or less.

-Weight average degree of polymerization-
The weight average polymerization degree of the specific cellulose acylate is preferably 200 or more and 1000 or less, and more preferably 500 or more and 1000 or less, from the viewpoint of suppressing thermal deformation while ensuring the crack resistance of the resin molded product.

Here, the weight average degree of polymerization is determined from the weight average molecular weight (Mw) by the following procedure.
First, the weight average molecular weight (Mw) of the specific cellulose acylate is measured in terms of polystyrene using a gel permeation chromatography apparatus (GPC apparatus: manufactured by Tosoh Corporation, HLC-8320GPC, column: TSKgel α-M) using tetrahydrofuran. Next, the degree of polymerization of the specific cellulose acylate is determined by dividing by the molecular weight of the constituent unit of the specific cellulose acylate.

-Degree of substitution-
The degree of substitution of the specific cellulose acylate is preferably 2.1 or more and 2.8 or less, and the degree of substitution is 2.2 or more and 2.8 or less, from the viewpoint of suppressing thermal deformation while ensuring the crack resistance of the resin molded product. Is more preferably 2.3 or more and 2.75 or less, and particularly preferably 2.35 or more and 2.75 or less.

Here, the degree of substitution is an index indicating the degree to which the hydroxyl group of cellulose is substituted with an acyl group. That is, the degree of substitution is an index indicating the degree of acylation of the specific cellulose acylate. Specifically, the degree of substitution means an intramolecular average of the number of substitutions in which three hydroxyl groups in the D-glucopyranose unit of cellulose acylate are substituted with acyl groups.
The degree of substitution is measured from the integral ratio of hydrogen derived from cellulose and the peak derived from acyl group by H ¹ -NMR (manufactured by JMN-ECA / JEOL RESONANCE).

-Propionyl group content-
In cellulose acetate propionate, the content of propionyl groups relative to cellulose acetate propionate is 39% by mass or more and 51% by mass or less in terms of suppressing thermal deformation while ensuring crack resistance of the resin molded product. The content is preferably 40% by mass or more and 50% by mass or less, and more preferably 41% by mass or more and 49% by mass or less.

-Ratio of propionyl group content to acetyl group content-
In the cellulose acetate propionate, the ratio of the degree of substitution between the acetyl group and the propionyl group (acetyl group / propionyl group) is 5/1 in terms of suppressing thermal deformation while ensuring the crack resistance of the resin molded product. The ratio is preferably 1/20 or less and more preferably 3/1 or more and 1/15 or less.

-Butyryl group content-
In the cellulose acetate butyrate, the propionyl group content relative to the cellulose acetate butyrate is 15% by mass or more and 55% by mass or less in terms of suppressing thermal deformation while ensuring crack resistance of the resin molded product. It is preferably 16% by mass or more and 54% by mass or less.

-Ratio of butyryl group content to acetyl group content-
In cellulose acetate butyrate, the ratio of the degree of substitution between acetyl group and butyryl group (acetyl group / butyryl group) is 5/1 in that cracking of the resin molded product is ensured and thermal deformation is suppressed. The ratio is preferably 1/20 or less and more preferably 4/1 or more and 1/15 or less.

Here, the content of the acetyl group, the content of the propionyl group, and the content of the butyryl group are determined by the following methods. Cellulose acetate propionate or cellulose acetate butyrate is analyzed by H ¹ -NMR (JMN-ECA / JEOL RESONANCE). In the case of cellulose acetate propionate, it is calculated from the integrated value of an acetyl group-derived peak, a propionyl group-derived peak, and a hydroxyl group-derived peak. In the case of cellulose acetate butyrate, it is calculated from an integrated value of an acetyl group-derived peak, a butyryl group-derived peak, and a hydroxyl group-derived peak.
And mass ratio of both is calculated | required from content of the propionyl group or butyryl group calculated | required by this method, and content of an acetyl group.

The production method of the specific cellulose acylate is not particularly limited, and examples thereof include acylation, low molecular weight (depolymerization), and, if necessary, deacetylation of cellulose. Further, a commercially available cellulose acetate propionate or a commercially available cellulose acetate butyrate may be produced by reducing the molecular weight (depolymerization) or the like so as to have a predetermined weight average molecular weight.

[Polylactic acid]
The resin composition according to the present embodiment contains poly (hydroxycarboxylic acid) other than polylactic acid. Polylactic acid is a polymer compound in which lactic acid is polymerized by an ester bond.

The polylactic acid has a poly L-lactic acid having a structural unit derived from L-lactic acid, a poly D-lactic acid having a structural unit derived from D-lactic acid, and a structural unit derived from L-lactic acid and D-lactic acid. Examples thereof include poly DL-lactic acid and the like, and mixtures thereof. Further, at least one of L-lactic acid and D-lactic acid may be copolymerized with L-lactic acid other than L-lactic acid and D-lactic acid or a monomer copolymerizable with D-lactic acid.

The monomer copolymerizable with L-lactic acid or D-lactic acid is not particularly limited, and examples thereof include the following monomers. Specifically, glycolic acid, dimethyl glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, 2-hydroxyvaleric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid Herbic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid and other polyvalent carboxylic acids and their anhydrides; ethylene glycol , Diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, , 6-hexanediol, 1,9-nonanediol, 3-methyl-1,5-pe Polyhydric alcohols such as tandiol, neopentyl glycol, tetramethylene glycol, 1,4-hexanedimethanol; polysaccharides such as cellulose; aminocarboxylic acids such as α-amino acids; 5-hydroxyvaleric acid, 2-hydroxycaproic acid, Hydroxycarboxylic acids such as 3-hydroxycaproic acid, 4-hydroxycaproic acid, 5-hydroxycaproic acid, 6-hydroxycaproic acid, 6-hydroxymethylcaproic acid, mandelic acid; glycolide, β-methyl-δ-valerolactone, and cyclic esters such as γ-valerolactone and ε-caprolactone.

The polymerization method of polylactic acid is not particularly limited, and examples thereof include known methods such as a condensation polymerization method and a ring opening polymerization method. For example, polylactic acid may be produced by a ring-opening polymerization method using lactide, which is a cyclic dimer of lactic acid; a polycondensation method in which at least one of L-lactic acid and D-lactic acid is directly subjected to dehydration condensation polymerization;

The weight average molecular weight (Mw) of polylactic acid is preferably 50,000 or more and 300,000 or less in terms of obtaining a resin molded product in which thermal deformation is suppressed while ensuring crack resistance, and 750,000. It is preferably 250,000 or less and more preferably 100,000 or more and 200,000 or less.
The average degree of polymerization of polylactic acid is preferably 700 or more and 4200 or less, and preferably 1400 or more and 2800 or less, from the viewpoint of obtaining a resin molded body in which thermal deformation is suppressed while ensuring crack resistance.

The weight average molecular weight (Mw) of polylactic acid is a value measured by gel permeation chromatograph (GPC). Specifically, for molecular weight measurement by GPC, Tosoh Co., Ltd., HLC-8320GPC was used as a measuring device, and Tosoh Co., Ltd. column TSKgel was used.
Use GMHHR-M + TSKgel GMHHR-M (7.8 mm ID 30 cm) with chloroform solvent. The weight average molecular weight (Mw) is calculated from the measurement result using a molecular weight calibration curve created with a monodisperse polystyrene standard sample.

[Poly (hydroxycarboxylic acid) other than polylactic acid]
The resin composition according to the present embodiment contains poly (hydroxycarboxylic acid) other than polylactic acid. Specific examples of the poly (hydroxycarboxylic acid) other than polylactic acid include a resin having a chemical structure represented by the general formula (2).

(In general formula (2), R ¹¹ represents an alkylene group having 2 to 10 carbon atoms. P represents an integer of 2 or more.)

In general formula (2), the alkylene group represented by R ¹¹ is preferably an alkylene group having 3 to 6 carbon atoms. The alkylene group represented by R ¹¹ may be either linear or branched. A branched shape is preferred from the viewpoint of obtaining a resin molded product having improved tensile elongation at break while suppressing a decrease in tensile elastic modulus of the resin molded product.

Here, in general formula (2), R ¹¹ represents an alkylene group. 1) R ¹¹ has an [O—R ¹¹ —C (═O) —] structure in which the same alkylene group is represented; 2) alkylene group R ¹¹ is different from a plurality of representative of ^{(R 11} is an alkylene group having different carbon numbers or ^{branched) [O-R 11 -C (} = O) -] structure ^{(i.e., [O-R 11A -C (} = O )-] [O—R ^11B —C (═O) —] structure).
That is, the poly (hydroxycarboxylic acid) other than polylactic acid may be a homopolymer of one kind of poly (hydroxycarboxylic acid) other than polylactic acid, or poly (hydroxycarboxylic acid) other than two or more kinds of polylactic acid. Acid) copolymer.

In the general formula (2), the upper limit of p is not particularly limited, and examples thereof include 20000 or less. The range of p is preferably 500 or more and 10,000 or less, and more preferably 1000 or more and 8,000 or less, from the viewpoint of obtaining a resin molded article having improved tensile elongation at break while suppressing a decrease in tensile elastic modulus.

Examples of hydroxyalkanoic acids that form poly (hydroxycarboxylic acids) other than polylactic acid include 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxy-3,3 -Dimethylbutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 3-hydroxyhexanoic acid, 2-hydroxycaproic acid, 2-hydroxyisocaproic acid, 6-hydroxycaproic acid, 3-hydroxy Examples include propionic acid, 3-hydroxy-2,2-dimethylpropionic acid, 3-hydroxyhexanoic acid, 2-hydroxy-n-octanoic acid and the like.

Among these, poly (hydroxycarboxylic acid) other than polylactic acid is a hydroxyalkanoic acid having 3 to 4 carbon atoms in that a resin molded product is obtained in which thermal deformation is suppressed while ensuring crack resistance. A copolymer with a branched hydroxyalkanoic acid having 5 or more and 7 or more carbon atoms (however, the carbon number is a number including carbon of a carboxy group) is preferable. In particular, a copolymer of 3-hydroxybutyric acid and 3-hydroxycaproic acid (a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate) is more preferable.

When poly (hydroxycarboxylic acid) other than polylactic acid is a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate, a copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate The copolymerization ratio of 3-hydroxyhexanoate to 3 mol% is preferably 3 mol% to 20 mol%, preferably 4 mol% to 15 mol%, and preferably 5 mol% to 12 mol%. More preferably. When the copolymerization ratio of 3-hydroxyhexanoate is in the range of 3 mol% or more and 20 mol% or less, it becomes easy to obtain a resin molded product that suppresses thermal deformation while ensuring crack resistance.

In addition, the measuring method of the copolymerization ratio of 3-hydroxyhexanoate to the copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate is measured as follows.
Using H ¹ -NMR, the hexanoate ratio is calculated from the integrated value of the peaks derived from the hexanoate terminal and the butyrate terminal.

The poly (hydroxycarboxylic acid) other than polylactic acid has a weight average molecular weight (Mw) of 10,000 to 1,000,000 (preferably 50,000 to 800,000, more preferably 100,000 to 600, 000 or less).
When the weight average molecular weight (Mw) of the poly (hydroxycarboxylic acid) other than polylactic acid is in the above range, a resin molded article having improved tensile elongation at break while suppressing a decrease in tensile elastic modulus can be obtained. Becomes easier to obtain.

The weight average molecular weight (Mw) of poly (hydroxycarboxylic acid) other than polylactic acid is a value measured by gel permeation chromatography (GPC). Specifically, for molecular weight measurement by GPC, Tosoh Co., Ltd., HPLC 1100 is used as a measuring device, and Tosoh Co., Ltd. column TSKgel GMHHR-M + TSKgel GMHHR-M (7.8 mm ID 30 cm) is used. Perform with chloroform solvent. The weight average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

[Specific ester compounds]
The specific ester compound is a compound having an ester group (—C (═O) O—) and having a molecular weight of 250 or more and 2000 or less (preferably 250 or more and 1000 or less, more preferably 250 or more and 600 or less). The resin composition according to the present embodiment includes at least one specific ester compound. In addition, when using together 2 or more types of specific ester compounds, the molecular weight of 250-2000 is used together, respectively.

Specific examples of the ester compound include fatty acid ester compounds and aromatic carboxylic acid ester compounds. Among these, as the specific ester compound, a fatty acid ester compound is preferable in that a resin molded body in which thermal deformation is suppressed while securing crack resistance of the obtained resin molded body is obtained.

Examples of fatty acid ester compounds include aliphatic monocarboxylic acid esters (acetic acid esters, etc.), aliphatic dicarboxylic acid esters (succinic acid esters, adipic acid ester-containing compounds, azelaic acid esters, sebacic acid esters, stearic acid esters, etc.), aliphatic Tricarboxylic acid ester (citrate ester, isocitrate ester, etc.), ester group-containing epoxidized compound (epoxidized soybean oil, epoxidized linseed oil, epoxidized rapeseed fatty acid isobutyl, epoxidized fatty acid 2-ethylhexyl), fatty acid methyl ester, Examples thereof include sugar esters.
Examples of the aromatic carboxylic acid ester compound include dimethyl phthalate, diethyl phthalate, bis (2-ethylhexyl) phthalate, and terephthalic acid ester.

Among these, aliphatic dicarboxylic acid esters and aliphatic tricarboxylic acid esters are preferable, and adipic acid esters are preferable in that a resin molded body in which thermal deformation is suppressed while ensuring crack resistance of the obtained resin molded body is obtained. A containing compound and a citric acid ester are more preferable, and an adipic acid ester-containing compound is more preferable.

The adipic acid ester-containing compound (compound containing adipic acid ester) is a compound of adipic acid ester alone or a mixture of adipic acid ester and a component other than adipic acid ester (a compound different from adipic acid ester) Indicates. However, the adipic acid ester-containing compound may contain 50% by mass or more of the adipic acid ester with respect to all components.

Examples of adipic acid esters include adipic acid diesters. Specific examples include adipic acid diesters represented by the following general formula (AE).

In General Formula (AE), R ^AE1 and RA ^E2 each independently represent an alkyl group or a polyoxyalkyl group [— (C _x H _2X —O) _y —R ^A1 ] (where R ^A1 represents an alkyl group) , X represents an integer from 1 to 10, and y represents an integer from 1 to 10.

In general formula (AE), the alkyl group represented by R ^AE1 and R ^AE2 is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group represented by R ^AE1 and R ^AE2 may be linear, branched, or cyclic, but is preferably linear or branched.
In the general formula (AE), in the polyoxyalkyl group [— (C _x H _2X —O) _y —R ^A1 ] represented by R ^AE1 and R ^AE2 , the alkyl group represented by R ^A1 has 1 to 6 carbon atoms. An alkyl group is preferable, and an alkyl group having 1 to 4 carbon atoms is more preferable. The alkyl group represented by R ^A1 may be linear, branched or cyclic, but is preferably linear or branched.

In general formula (AE), the group represented by each symbol may be substituted with a substituent. Examples of the substituent include an alkyl group, an aryl group, and a hydroxyl group.

On the other hand, examples of the citrate ester include alkyl esters of citric acid having 1 to 12 carbon atoms (preferably 1 to 8 carbon atoms). The citrate ester is an alkylcarboxylic acid anhydride (for example, linear or branched chain such as acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, etc., having 2 or more and 6 or less carbon atoms (preferably 2 or more and 3 or less). Citric acid ester acylated with alkyl carboxylic acid anhydride).

[Polymer of core-shell structure]
The resin composition according to the present embodiment may contain a core-shell structure polymer having a core layer and a shell layer containing a (meth) acrylic polymer on the surface of the core layer, if necessary. . A polymer having a core-shell structure is, for example, elastic at room temperature (25 ° C.) and the same as a thermoplastic resin at a high temperature in that a resin molded body in which thermal deformation is suppressed while ensuring crack resistance is obtained. It is preferable to have a softening property (thermoplastic elastomer).

The core-shell structure polymer is a core-shell structure polymer having a core layer and a shell layer on the surface of the core layer.
A polymer having a core-shell structure is a polymer in which a core layer is an innermost layer and a shell layer is an outermost layer (for example, a polymer of (meth) acrylic acid alkyl ester is graft-polymerized to a polymer to be a core layer to form a shell. The polymer may be a layer.).
Note that one or more other layers (for example, other layers of 1 to 6 layers) may be provided between the core layer and the shell layer. In addition, when it has another layer, the polymer of a core shell structure may be a polymer obtained by graft polymerization of a plurality of types of polymers to the polymer to be the core layer.

The core layer is not particularly limited, but is preferably a rubber layer. Examples of the rubber layer include layers such as (meth) acrylic rubber, silicone rubber, styrene rubber, conjugated diene rubber, α-olefin rubber, nitrile rubber, urethane rubber, polyester rubber, polyamide rubber, and copolymer rubbers of two or more of these. It is done.
Among these, the rubber layer is preferably a layer of (meth) acrylic rubber, silicone rubber, styrene rubber, conjugated diene rubber, α-olefin rubber, two or more copolymer rubbers, and the like.
The rubber layer may be a rubber layer that is crosslinked by copolymerizing a crosslinking agent (divinylbenzene, allyl acrylate, butylene glycol diacrylate, etc.).

Examples of the (meth) acrylic rubber include polymer rubber obtained by polymerizing a (meth) acrylic component (for example, an alkyl ester of (meth) acrylic acid having 2 to 6 carbon atoms).
Examples of the silicone rubber include rubber composed of a silicone component (polydimethylsiloxane, polyphenylsiloxane, etc.).
Examples of the styrene rubber include polymer rubber obtained by polymerizing a styrene component (styrene, α-methylstyrene, etc.).
Examples of the conjugated diene rubber include polymer rubber obtained by polymerizing a conjugated diene component (butadiene, isoprene, etc.).
Examples of the α-olefin rubber include polymer rubber obtained by polymerizing an α-olefin component (ethylene, propylene, 2-methylpropylene).
Examples of the copolymer rubber include a copolymer rubber obtained by polymerizing two or more kinds of (meth) acrylic components, a copolymer rubber obtained by polymerizing a (meth) acrylic component and a silicone component, and a (meth) acrylic component and a conjugated diene. Examples thereof include a copolymer of a component and a styrene component.

In the polymer of (meth) acrylic acid alkyl ester contained in the shell layer, the (meth) acrylic acid alkyl ester includes methyl (meth) acrylate, ethyl (meth) acrylate, and n-propyl (meth) acrylate. , N-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, stearyl (meth) acrylate And octadecyl (meth) acrylate. In the (meth) acrylic acid alkyl ester, at least a part of hydrogen of the alkyl chain may be substituted. Examples of the substituent include an amino group, a hydroxyl group, and a halogen group.

Among these, as a polymer of (meth) acrylic acid alkyl ester, the number of carbon atoms of the alkyl chain is obtained in that a resin molded body in which thermal deformation is suppressed while ensuring crack resistance of the obtained resin molded body is obtained. Is preferably a polymer of (meth) acrylic acid alkyl ester having 1 or more and 8 or less, more preferably a polymer of (meth) acrylic acid alkyl ester having 1 or more and 2 or less carbon atoms in the alkyl chain, and a carbon number of the alkyl chain. More preferred is a polymer of 1 (meth) acrylic acid alkyl ester. In particular, copolymers of two or more alkyl acrylates having different alkyl chain carbon numbers are preferred.

The content of the polymer in the shell layer in the core-shell structure polymer is preferably 1% by mass or more and 40% by mass or less, more preferably 3% by mass or more and 30% by mass or less, with respect to the entire core-shell structure polymer. More preferably, it is at least 15% by mass.

The core-shell structure polymer according to this embodiment may be a commercially available product or may be produced by a known method.
Examples of commercially available products include “Metablen” manufactured by Mitsubishi Chemical, “Kane Ace” manufactured by Kaneka, “Paraloid” manufactured by Dow Chemical, and the like. These may be used alone or in combination of two or more.

Known methods include emulsion polymerization. Specifically, the following method is exemplified as the production method. First, a mixture of monomers is emulsion-polymerized to form core particles (core layer), and then a mixture of other monomers is emulsion-polymerized in the presence of core particles (core layer) to form core particles (core layer). A polymer having a core-shell structure in which a shell layer is formed around is obtained.
When another layer is formed between the core layer and the shell layer, it is composed of the target core layer, the other layer, and the shell layer by repeating emulsion polymerization of a mixture of other monomers. A core-shell polymer is obtained.

The average primary particle size of the core-shell structure polymer according to the present embodiment is not particularly limited, but it is 50 nm in that thermal deformation is suppressed while ensuring crack resistance of the obtained resin molded body. The thickness is preferably 500 nm or less, more preferably 50 nm or more and 400 nm or less, particularly preferably 100 nm or more and 300 nm or less, and most preferably 150 nm or more and 250 nm or less.
In addition, an average primary particle diameter means the value measured by the following method. The particles are observed with a scanning electron microscope, the maximum primary particle diameter is defined as the primary particle diameter, and the primary particle diameter is measured and averaged for 100 particles. Specifically, it can be determined by observing the dispersion form of the polymer having a core-shell structure in the resin composition with a scanning electron microscope.

[(Meth) acrylic polymer]
The resin composition which concerns on this embodiment may contain the (meth) acryl polymer in the matrix except the polymer of a core shell structure as needed. In addition, when a (meth) acrylic polymer is contained in the matrix, there is a tendency that thermal deformation of the obtained resin molded body is easily suppressed.
In the present specification, the (meth) acrylic polymer is not particularly limited, and may be, for example, a polymer including a structural unit derived from a (meth) acrylic acid ester. Among these, the (meth) acrylic polymer is preferably a polymer containing a structural unit derived from a (meth) acrylic acid alkyl ester. The (meth) acrylic polymer may be, for example, a homopolymer containing only one type of structural unit derived from (meth) acrylic acid ester, or one or two structural units derived from (meth) acrylic acid ester. The copolymer containing the above may be sufficient.

For example, when the (meth) acrylic polymer is a copolymer containing a structural unit derived from a (meth) acrylic polymer alkyl ester, the structural unit derived from the (meth) acrylic polymer alkyl ester is a copolymer. It is good that they are 50 mass% or more and 99 mass% or less (preferably 60 mass% or more and 95 mass% or less, preferably 70 mass% or more and 95 mass% or less). The structural unit other than the structural unit derived from the (meth) acrylic polymer alkyl ester is 1% by mass to 50% by mass (preferably 5% by mass to 40% by mass, preferably 5% by mass to 30% by mass). % Or less).

Examples of the structural unit derived from the (meth) acrylic acid ester that the (meth) acrylic polymer has include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylic acid n- Propyl, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, Neopentyl (meth) acrylate, n-hexyl (meth) acrylate, isohexyl (meth) acrylate, n-heptyl (meth) acrylate, isoheptyl (meth) acrylate, n-octyl (meth) acrylate, (meta ) Isooctyl acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, (meth ) Structural units derived from (meth) acrylic acid alkyl esters such as n-octadecyl acrylate; Structural units derived from (meth) acrylic acid phenyl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate; Can be mentioned.

The upper limit of the weight average molecular weight of the (meth) acrylic polymer is not particularly limited. It is good that it is 30000 or less at the point from which the resin molded object by which a thermal deformation is suppressed is ensured, ensuring crack resistance. Further, the upper limit of the weight average molecular weight may be less than 30000, or 28000 or less. Moreover, the lower limit of the weight average molecular weight of a (meth) acrylic polymer is not specifically limited, For example, it is 15000 or more. The lower limit of the weight average molecular weight may be 20000 or more. Moreover, thermal deformation is more easily suppressed by using a (meth) acrylic polymer having a weight average molecular weight of 30000 or less.

The weight average molecular weight of the (meth) acrylic polymer is a value measured by gel permeation chromatography (GPC). Specifically, the molecular weight measurement by GPC is carried out with a tetrahydrofuran solvent using HLC-8320GPC manufactured by Tosoh Corporation as a measuring apparatus and using a column TSKgelα-M manufactured by Tosoh Corporation. The weight average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

[Other ingredients]
The resin composition according to the present embodiment may further include other components than those described above as necessary. Examples of other components include flame retardants, compatibilizers, antioxidants, mold release agents, light proofing agents, weathering agents, colorants, pigments, modifiers, anti-drip agents, antistatic agents, and hydrolysis inhibitors. , Fillers, reinforcing agents (glass fiber, carbon fiber, talc, clay, mica, glass flake, milled glass, glass beads, crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, etc.).
Moreover, you may add components (additive), such as an acid acceptor and a reactive trap agent for preventing acetic acid release as needed. Examples of the acid acceptor include oxides such as magnesium oxide and aluminum oxide; metal hydroxides such as magnesium hydroxide, calcium hydroxide, aluminum hydroxide and hydrotalcite; calcium carbonate; talc;
Examples of the reactive trapping agent include an epoxy compound, an acid anhydride compound, and carbodiimide.
The content of these components is preferably 0% by mass to 5% by mass with respect to the total amount of the resin composition. Here, “0 mass%” means that other components are not included.

The resin composition according to the present embodiment may contain other resins than the above resins (cellulose acetate propionate and polymethyl methacrylate). However, when other resins are included, the content of the other resins with respect to the total amount of the resin composition is preferably 5% by mass or less, and preferably less than 1% by mass. It is more preferable that other resins are not contained (that is, 0% by mass).
Examples of other resins include conventionally known thermoplastic resins, and specifically, polycarbonate resins; polypropylene resins; polyester resins; polyolefin resins; polyester carbonate resins; polyphenylene ether resins; Polyethersulfone resin; Polyarylene resin; Polyetherimide resin; Polyacetal resin; Polyvinyl acetal resin; Polyketone resin; Polyetherketone resin; Polyetheretherketone resin; Polyarylketone resin; Polyethernitrile resin; Selected from the group consisting of imidazole resins; polyparabanic acid resins; aromatic alkenyl compounds, methacrylic acid esters, acrylic acid esters, and vinyl cyanide compounds. Vinyl polymer or copolymer obtained by polymerizing or copolymerizing one or more kinds of vinyl monomers; diene-aromatic alkenyl compound copolymer; vinyl cyanide-diene-aromatic alkenyl compound copolymer Aromatic alkenyl compound-diene-vinyl cyanide-N-phenylmaleimide copolymer; vinyl cyanide- (ethylene-diene-propylene (EPDM))-aromatic alkenyl compound copolymer; vinyl chloride resin; chlorinated chloride Vinyl resin; and the like. Further, a core-shell type butadiene-methyl methacrylate copolymer may also be mentioned. These resins may be used alone or in combination of two or more.

[Mass ratio of each component to specific cellulose acylate]
In the resin composition according to this embodiment, the ratio ((B) / (A)) of the mass (B) of polylactic acid to the mass (A) of the specific cellulose acylate is 0.05 or more and 0.5 or less.
Moreover, ratio ((C) / (A)) of mass (C) of poly (hydroxycarboxylic acid) other than polylactic acid to mass (A) of cellulose acylate is 0.02 or more and 0.2 or less.
Furthermore, the ratio ((D) / (A)) of the mass (D) of the ester compound having a molecular weight of 250 or more and 2000 or less to the mass (A) of the cellulose acylate is 0.05 or more and 0.15 or less.

In the resin composition according to the present embodiment, the above (B) / (A) is 0.05 or more and 0.3 in that a resin molded body in which thermal deformation is suppressed while ensuring crack resistance is obtained. Or less, more preferably 0.05 or more and 0.2 or less. In the same point, (C) / (A) is preferably 0.02 or more and 0.1 or less, and more preferably 0.05 or more and 0.1 or less. (D) / (A) is preferably 0.06 or more and 0.12 or less, and more preferably 0.08 or more and 0.1 or less.

When the resin composition according to the present embodiment includes a polymer having a core-shell structure, the mass of the specific cellulose acylate (A) is obtained in that a resin molded body in which thermal deformation is suppressed while securing crack resistance is obtained. ) The ratio ((E) / (A)) of the mass (E) of the polymer having a core-shell structure to ()) is preferably 0.02 or more and 0.2 or less, and preferably 0.05 or more and 0.1 or less.
In addition, when the resin composition according to the present embodiment contains a (meth) acrylic polymer, the resin composition of the specific cellulose acylate is obtained in that a resin molded body in which thermal deformation is suppressed while securing crack resistance is obtained. The ratio ((F) / (A)) of the mass (F) of the (meth) acrylic polymer to the mass (A) is preferably 0.01 or more and 0.2 or less, and 0.03 or more and 0.15 or less. Is preferred.

In addition, specific cellulose acylate, polylactic acid, poly (hydroxycarboxylic acid) other than polylactic acid, ester compound having a molecular weight of 250 or more and 2000 or less, and the content of the polymer having a core-shell structure, and these components for the specific cellulose acylate The mass ratio is determined by measuring the resin composition and the resin molding to be measured using nuclear magnetic resonance (NMR), infrared spectroscopy (IR), liquid chromatograph mass spectrometry (LC-MS), gas chromatograph mass spectrometry (GC). -MS) and other analytical methods such as mass spectrometry. The same applies to the case where the resin composition and the resin molded body contain at least one of a polymer having a core-shell structure and a (meth) acrylic polymer.

[Load deflection temperature x Steel ball height in crack resistance test]
As described above, the resin composition according to the second embodiment provides a resin molded body in which the product of the deflection temperature under load (° C.) and the steel ball height (m) in the crack resistance test is 80 or more. . The product of the deflection temperature under load (° C.) and the steel ball height (m) in the crack resistance test is preferably 85 or more, and preferably 90 or more. The upper limit of the product of the deflection temperature under load (° C.) and the steel ball height (m) in the crack resistance test is not particularly limited, and examples include 200 or less. Even if only the heat deflection temperature is high, the ease of cracking of the resin composition is difficult to improve, and even if the steel ball height (m) of the crack resistance test is large, thermal deformation is difficult to be suppressed. Therefore, when the product of the deflection temperature under load (° C.) and the steel ball height (m) in the crack resistance test is 80 or more, a resin molded body that is difficult to be thermally deformed and hard to crack (that is, excellent in durability, In addition, a resin molded body that is not easily thermally deformed is obtained.

In addition, the lower limit value of the deflection temperature under load (° C.) is preferably, for example, 70 ° C. or more in that a resin molded body that is not easily thermally deformed is obtained. Moreover, the lower limit value of the steel ball height in the crack resistance test is preferably, for example, 0.9 m or more in that a resin molded body that is difficult to break is obtained. The measurement of the deflection temperature under load (° C.) and the height (m) of the steel ball in the crack resistance test are measured by the method described in the examples described later.

In order to obtain a resin molded body in which the product of the deflection temperature under load (° C.) and the steel ball height (m) in the crack resistance test is 80 or more, for example, the following is preferable. As a composition in a resin composition, it is good to contain the specific cellulose acylate, polylactic acid, a specific ester compound, and the polymer of a core shell structure in a well-balanced ratio. Specifically, the mass ratio of each component to the aforementioned specific cellulose acylate (polylactic acid / specific cellulose acylate ((B) / (A)), specific ester compound / specific cellulose acylate ((C) / (A )) And a polymer having a core-shell structure / specific cellulose acylate ((D) / (A))) are preferably contained in the above-described ratio.

In the resin composition according to this embodiment, the content of the specific cellulose acylate is preferably 50% by mass or more of the entire resin composition, preferably 70% by mass or more, and 90% by mass or more. Is good. In addition, the resin composition according to the present embodiment may include specific cellulose acylate, polylactic acid, poly (hydroxycarboxylic acid) other than polylactic acid, an ester compound having a molecular weight of 250 to 2000, and if necessary. The total content of the polymer having a good core-shell structure and the (meth) acrylic polymer is preferably 95% by mass or more, 99% by mass or more, and 100% by mass with respect to the entire resin composition. May be.

[Method for Producing Resin Composition]
The resin composition according to the present embodiment includes, for example, a step of preparing a resin composition containing specific cellulose acylate, polylactic acid, poly (hydroxycarboxylic acid) other than polylactic acid, and an ester compound having a molecular weight of 250 to 2000. Have.
The resin composition according to this embodiment includes a specific cellulose acylate, polylactic acid, an ester compound having a molecular weight of 250 to 2000, and a core-shell structure polymer, and, if necessary, a core-shell structure polymer and (meth) acrylic. It is produced by melt-kneading a mixture containing at least one of the polymers and other components. In addition, the resin composition according to the present embodiment is produced, for example, by dissolving the above components in a solvent.
Examples of the melt-kneading means include known means, and specific examples include a twin screw extruder, a Henschel mixer, a Banbury mixer, a single screw extruder, a multi-screw extruder, and a kneader.

<Resin molding>
The resin molded body according to the present embodiment includes the resin composition according to the present embodiment. That is, the resin molded body according to the present embodiment is configured with the same composition as the resin composition according to the present embodiment.

The molding method of the resin molded body according to the present embodiment is not particularly limited, and includes injection molding, extrusion molding, blow molding, hot press molding, calendar molding, coating molding, cast molding, dipping molding, vacuum molding, transfer molding, and the like. A well-known shaping | molding method is mentioned. The resin molded body may be an injection molded body and an extrusion molded body obtained by any one of injection molding and extrusion molding. The resin molded body is preferably an injection molded body obtained by injection molding in that the degree of freedom in shape is high.

The cylinder temperature of injection molding is, for example, 200 ° C. or more and 300 ° C. or less, and preferably 240 ° C. or more and 280 ° C. or less. The mold temperature for injection molding is, for example, 40 ° C. or higher and 90 ° C. or lower, and more preferably 60 ° C. or higher and 80 ° C. or lower.
The injection molding may be performed using a commercially available apparatus such as NEX500 manufactured by Nissei Plastic Industrial Co., Ltd., NEX150 manufactured by Nissei Plastic Industrial Co., Ltd., NEX70000 manufactured by Nissei Plastic Industrial Co., Ltd., PNX40 manufactured by Nissei Plastic Industrial Co., Ltd., SE50D manufactured by Sumitomo Machinery Co., Ltd. Good.
The cylinder temperature of extrusion molding is, for example, 200 ° C. or more and 300 ° C. or less, and preferably 240 ° C. or more and 280 ° C. or less. For extrusion molding, a known apparatus may be applied.

The resin molded body according to the present embodiment is suitably used for applications such as electronic / electrical equipment, office equipment, home appliances, automobile interior materials, toys, and containers. More specifically, housings for electronic / electrical equipment and household appliances; various parts of electronic / electrical equipment and household electrical appliances; automobile interior parts; block assembly toys; plastic models; storage cases such as CD-ROMs and DVDs; Tableware; beverage bottle; food tray; wrapping material; film; sheet;

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. Note that “part” means “part by mass” unless otherwise specified.

<Preparation of specific cellulose acylate>
Three types of cellulose acetate propionate (CAP1 to CAP3) and cellulose acetate butyrate (CAB1 to CAB3) were prepared. The prepared specific cellulose acylates are shown in Table 1. The concentration of propionyl group and butyryl group was measured according to the method described above.

(Preparation of polylactic acid)
Three types of polylactic acid were prepared. The prepared polylactic acid is shown in Table 2.

(Preparation of poly (hydroxycarboxylic acid) other than polylactic acid)
Three types of poly (hydroxycarboxylic acid) other than polylactic acid were prepared. The prepared poly (hydroxycarboxylic acid) other than polylactic acid is shown in Table 3.

(Preparation of ester compound)
Three types of ester compounds were prepared. Table 4 shows the prepared ester compounds.

(Preparation of polymer with core-shell structure)
Three types of polymers having a core-shell structure were prepared. Table 5 shows the prepared polymers having a core-shell structure.

In Table 4, the structure of the polymer having a core-shell structure is as follows.
“Metablene W-600A (Mitsubishi Chemical Corporation)”: Core layer; 2-ethylhexyl acrylate and n-butyl acrylate homopolymer rubber / shell layer; Methyl methacrylate homopolymer rubber; Average primary particles Diameter = 300nm
“Metabrene S-2006 (manufactured by Mitsubishi Chemical Corporation)”: core layer; polymer rubber / shell layer containing polysiloxane as a polymerization component; alkyl methacrylate; average primary particle size = 200 nm
“Paraloid EXL2315 (manufactured by Dow Chemical Co.)”: core layer; butyl acrylate rubber / shell: methyl methacrylate polymer; average primary particle size = 300 nm

(Preparation of (meth) acrylic polymer)
Three types of (meth) acrylic polymers were prepared. The prepared (meth) acrylic polymer is shown in Table 6.

<Examples 1 to 50 and Comparative Examples 1 to 17>
-Kneading and injection molding-
Cylinder temperature was prepared according to Table 9 and Table 10 with the charging composition ratios shown in Table 7 and Table 8, and kneaded with a biaxial kneading apparatus (TEX41SS, manufactured by Toshiba Machine Co., Ltd.). Resin composition (pellet) Got.
About the obtained pellet, using an injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd., NEX140III), the injection peak pressure does not exceed 180 MPa, and the molding temperature (cylinder temperature) and mold temperature shown in Table 9 and Table 10, An ISO multipurpose dumbbell (measurement part width 10 mm × thickness 4 mm) and a D2 test piece (60 mm × 60 mm × thickness 2 mm) were molded.

[Evaluation]
-Measurement of deflection temperature under load-
Using the obtained ISO multi-purpose dumbbell, the deflection temperature under a load of 0.45 MPa was measured by an HDT measuring device (HDT 3A-2, manufactured by Toyo Seiki Seisakusho Co., Ltd.) according to a method according to ISO 75 (2004).

The obtained D2 test piece was sandwiched between two SUS304 jigs having a thickness of 100 mm × 100 mm square and a square opening of 40 mm × 40 mm square inside, and a thickness of 40 mm × 40 mm square. By fixing 8 places with a thin bolt nut having an outer diameter of 5 mm, the test piece is fixed in a form in which 40 mm × 40 mm is exposed. When a 500 g steel ball was dropped vertically onto a D2 test piece through a vinyl chloride pipe, the steel ball drop height at which the test piece cracked was evaluated.

In Tables 7 and 8, “AC” represents cellulose acylate, “PLA” represents polylactic acid, “PHC” represents poly (hydroxycarboxylic acid) other than polylactic acid, and “ES” represents In the ester compound, “C / S” represents a polymer having a core-shell structure, and “Ac” represents a (meth) acrylic polymer.
In Tables 9 and 10, “T × H” represents the product of the measurement of the deflection temperature under load (° C.) and the steel ball height (m) in the crack resistance test.

From the above results, it can be seen that in this example, the evaluation results of the deflection temperature under load and crack resistance are better than in the comparative example.
Although the invention has been described in detail and with reference to specific embodiments, various changes and modifications can be made without departing from the spirit and scope of the invention.
This application claims priority based on a Japanese patent application filed on March 6, 2018 (Japanese Patent Application No. 2018-039552).

Claims

Cellulose acylate comprising at least one selected from cellulose acetate propionate and cellulose acetate butyrate;
A polyhydroxyalkanoate containing polylactic acid and a poly (hydroxycarboxylic acid) other than the polylactic acid;
An ester compound having a molecular weight of 250 to 2000,
Including
The ratio ((B) / (A)) of the mass (B) of the polylactic acid to the mass (A) of the cellulose acylate is 0.05 or more and 0.5 or less, and the mass (A) of the cellulose acylate The ratio ((C) / (A)) of the mass (C) of the poly (hydroxycarboxylic acid) other than the polylactic acid to 0.02 or more and 0.2 or less, and the mass (A) of the cellulose acylate The resin composition whose ratio ((D) / (A)) of mass (D) of the ester compound is 0.05 or more and 0.15 or less.
The resin composition according to claim 1, wherein the product of the deflection temperature under load and the drop height of the hard ball in the crack resistance test is 80 or more.
Cellulose acylate comprising at least one selected from cellulose acetate propionate and cellulose acetate butyrate;
A polyhydroxyalkanoate containing polylactic acid and a poly (hydroxycarboxylic acid) other than the polylactic acid;
An ester compound having a molecular weight of 250 to 2000,
Including
A resin composition having a product of a deflection temperature under load and a drop height of a hard ball in a crack resistance test of 80 or more.
The resin composition according to any one of claims 1 to 3, wherein the ester compound is a fatty acid ester compound.
The resin composition according to claim 4, wherein the fatty acid ester compound is a compound containing an adipic acid ester.
And a core-shell polymer having a core layer and a shell layer containing a (meth) acrylic polymer on the surface of the core layer, and the mass of the polymer of the core-shell structure relative to the mass of the cellulose acylate (A) The resin composition according to any one of claims 1 to 5, wherein the ratio (E) ((E) / (A)) is 0.01 or more and 0.2 or less.
The resin composition according to claim 6, wherein the shell layer of the polymer having the core-shell structure includes a (meth) acrylic polymer of (meth) acrylic acid alkyl ester having an alkyl chain having 1 to 8 carbon atoms.
The resin composition according to claim 6, wherein the shell layer of the polymer having the core-shell structure contains a copolymer of two or more kinds of (meth) acrylic acid alkyl esters having different alkyl chain carbon numbers.
The resin composition according to any one of claims 1 to 8, further comprising a (meth) acrylic polymer in the matrix.
The (meth) acrylic polymer in the matrix is a polymer having a structural unit derived from a (meth) acrylic acid alkyl ester, and the (meth) acrylic acid alkyl ester relative to the mass (A) of the cellulose acylate. The resin composition according to claim 9, wherein the ratio ((F) / (A)) of the mass (F) of the polymer having the derived structural unit is 0.01 or more and 0.1 or less.
The resin composition according to claim 9 or 10, wherein the (meth) acrylic polymer in the matrix has a weight average molecular weight of 30000 or less.
A resin molded article comprising the resin composition according to any one of claims 1 to 11.
The resin molded body according to claim 12, wherein the resin molded body is an injection molded body.