WO2012153660A1 - Nucleating agent, and crystalline polymer composition containing said nucleating agent - Google Patents

Abstract

A nucleating agent comprising a crystalline polymer, wherein the crystalline polymer is a derivative produced by the esterification or etherification of a xylan having a repeating structural unit represented by structural formula (1) and has a number average molecular weight ranging from 3,000 to 150,000 in terms of polystyrene as measured by a gel permeation chromatography method using an organic solvent.

Description

Nucleating agent and crystalline polymer composition containing the nucleating agent

The present invention relates to a nucleating agent and a crystalline polymer composition containing the nucleating agent, and the crystalline polymer composition is used as a molding material for industrial parts, containers, packaging materials and the like.

Olefin-based polymer compounds containing α-olefins such as polyethylene and polypropylene, polyester-based polymer compounds containing aromatic carboxylic acids such as terephthalic acid, and biodegradable polyesters containing biodegradable aliphatic carboxylic acids A polymer has a slow crystallization rate after heat molding (crystallization does not start unless the temperature is low), and there are problems of prolonged molding cycle during processing and deformation due to crystallization after molding.

As means for solving these problems, addition of a nucleating agent that rapidly generates fine crystals is known.
However, existing typical nucleating agents include sodium benzoate, 4-tert-butylbenzoic acid aluminum salt, carboxylic acid metal salts such as sodium adipate, sodium bis (4-tert-butylphenyl) phosphate, sodium-2 Phosphate metal salts such as 2,2'-methylenebis (4,6-ditert-butylphenyl) phosphate, polyhydric alcohol derivatives such as dibenzylidene sorbitol, bis (methylbenzylidene) sorbitol, bis (dimethylbenzylidene) sorbitol, etc. This compound is incompatible with the crystalline polymer and has a relatively low molecular weight, so there is insufficient intermolecular interaction and there is room for improvement in the nucleation effect. For example, the expected addition effect may not be sufficiently exhibited.
In order to sufficiently exhibit the biodegradability of the biodegradable aliphatic carboxylic acid, the nucleating agent is also preferably composed of a biomass-derived material.

In order to solve the above problems, it is necessary to develop a nucleating agent that uses biomass and is more compatible than conventional nucleating agents.

As a similar prior art, there is a crystalline polymer composition in which chitin or chitosan is added to polylactic acid or the like (see Patent Document 1). However, chitin and chitosan have no thermoplasticity, and since the repeating unit is glucosamine (or an acetyl derivative thereof), it has many polar groups, that is, an amino group (or an acetamide group) and a hydroxyl group. Therefore, there is a problem in dispersibility and compatibility, and the effect is not yet satisfactory.

JP 2007-77232 A

This invention makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention is a biomass-derived nucleating agent in which the problems of dispersibility, compatibility, and bleed-out resistance are suppressed, and a crystalline polymer excellent in moldability comprising the nucleating agent. An object is to provide a composition.

In order to solve the above-mentioned problems, the present inventors have made extensive studies and as a result, obtained the following findings.
That is, the inventors have found that xylan and a derivative having a specific structure of xylan have an excellent function as a nucleating agent, and have completed the present invention.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A derivative obtained by esterification or etherification of xylan having a repeating structural unit represented by the following structural formula (1), and having a polystyrene-reduced number average molecular weight of 3, measured by gel permeation chromatography A crystalline polymer nucleating agent characterized by being in the range of 000 to 150,000.

<2> A derivative obtained by esterification of xylan having a repeating structural unit represented by the following structural formula (1), and having a polystyrene equivalent number average molecular weight of 3,000 to 150 measured by gel permeation chromatography It is a crystalline polymer nucleating agent characterized by being in the range of 1,000.

<3> A derivative obtained by esterifying xylan having a repeating structural unit represented by the following structural formula (1) with an alkanoyl group having 2 to 12 carbon atoms, and converted to polystyrene as measured by gel permeation chromatography A crystalline polymer nucleating agent having a number average molecular weight in the range of 3,000 to 150,000.

<4> A crystalline polymer composition comprising the crystalline polymer nucleating agent according to any one of <1> to <3>.
<5> The crystalline polymer composition according to <4>, wherein the crystalline polymer is a biodegradable polyester polymer.
<6> The crystalline polymer composition according to <4>, wherein the crystalline polymer is a polylactic acid polymer.
<7> The crystalline polymer composition according to <4>, wherein the crystalline polymer is a microorganism-produced polyester polymer.
<8> The crystalline polymer composition according to <4>, wherein the crystalline polymer is a polyolefin polymer.
<9> The crystalline polymer composition according to <4>, wherein the crystalline polymer is a polypropylene resin.
<10> A crystalline polymer composition comprising the xylan derivative precursor according to any one of <1> to <3>.
<11> The crystalline polymer composition according to <10>, wherein the crystalline polymer is a biodegradable polyester polymer.
<12> The crystalline polymer composition according to <10>, wherein the crystalline polymer is a polylactic acid polymer.
<13> The crystalline polymer composition according to <10>, wherein the crystalline polymer is a microorganism-produced polyester polymer.
<14> The crystalline polymer composition according to <10>, wherein the crystalline polymer is a polyolefin polymer.
<15> The crystalline polymer composition according to <10>, wherein the crystalline polymer is a polypropylene resin.

According to the present invention, the above-mentioned problems can be solved and the object can be achieved, and the crystalline polymer molding cycle can be shortened by improving the crystallization temperature of the crystalline polymer, and the stability of the molded product. It is possible to provide a nucleating agent having an excellent improvement effect and a crystalline polymer composition containing the nucleating agent.

FIG. 1 is a diagram showing the ¹ H-NMR spectrum of xylan acetate. FIG. 2 is a diagram showing a ¹ H-NMR spectrum of xylampropionate. FIG. 3 shows the ¹ H-NMR spectrum of xylan hexanoate. FIG. 4 shows the ¹ H-NMR spectrum of xylan decanoate. FIG. 5 is a diagram showing a ¹ H-NMR spectrum of xylan laurate. FIG. 6 shows the ¹ H-NMR spectrum of xylan butyrate. FIG. 7 is a diagram showing a ¹ H-NMR spectrum of xylan valerate. FIG. 8A is a diagram showing an example of a DSC curve at the time of the second temperature increase of a mixture (film) of poly-L-lactic acid (PLLA) and a xylan derivative or a film made only of PLLA. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 8B is a diagram showing an example of a DSC curve at the time of the second temperature increase of a mixture (film) of poly-D-lactic acid (PDLA) and a xylan derivative or a film made only of PDLA. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 9A is a diagram showing an example of a DSC curve at the time of a second temperature increase of a mixture (film) of PLLA and a xylan derivative (xylampropionate) or a film made only of PLLA. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 9B is a diagram showing an example of a DSC curve at the time of a second temperature increase of a mixture (film) of PLLA and a xylan derivative (xylan butyrate) or a film made only of PLLA. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 10A is a diagram showing an example of a DSC curve when the temperature (temperature) of a mixture (film) of PLLA and a xylan derivative (xylampropionate) is lowered. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 10B is a diagram showing an example of a DSC curve when the temperature of the mixture (film) of PLLA and a xylan derivative (xylan butyrate) is lowered. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 10C is a diagram showing an example of a DSC curve when the temperature of a film made only of PLLA is lowered. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 10D is a diagram showing an example of a DSC curve when the temperature (temperature) of a mixture (film) of PDLA and a xylan derivative (xylampropionate) is lowered. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 10E is a diagram showing an example of a DSC curve at the time of cooling of a mixture (film) of PDLA and a xylan derivative (xylan butyrate). The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 10F is a diagram showing an example of a DSC curve when the temperature of a film made only of PDLA is lowered. The vertical axis represents the direction of heat generation, and the horizontal axis represents temperature (° C.). FIG. 11A is a diagram obtained by observing a mixture (film) of PLLA and a xylan derivative or a film made only of PLLA with a polarizing microscope. The scale bar represents 100 μm. FIG. 11B is a diagram in which a mixture (film) of PDLA and a xylan derivative or a film made only of PDLA is observed with a polarizing microscope. The scale bar represents 100 μm. FIG. 12 is a graph showing an example of the relationship between the annealing time and the crystallinity of a mixture (film) of PLLA and a xylan derivative at an annealing temperature of 100 ° C. or a film made only of PLLA. The vertical axis represents crystallinity (%), and the horizontal axis represents annealing time (minutes). FIG. 13 is a graph showing an example of the relationship between the annealing time and haze value of a mixture (film) of PLLA and a xylan derivative at an annealing temperature of 100 ° C. or a film made only of PLLA. The vertical axis represents haze value (%), and the horizontal axis represents annealing time (minutes). FIG. 14 is a photograph showing an example of the appearance of a mixture (film) of PLLA and a xylan derivative or a film made only of PLLA. FIG. 15 is a graph showing an example of the relationship between the annealing time and the coefficient of thermal expansion of a mixture (film) of PLLA and a xylan derivative at an annealing temperature of 100 ° C. or a film made only of PLLA. The vertical axis represents the coefficient of thermal expansion (%), and the horizontal axis represents the annealing time (minutes).

Hereinafter, preferred embodiments of the present invention will be described in detail.

(Nucleating agent)
The nucleating agent of the present invention is obtained by esterification or etherification of xylan having a repeating structural unit represented by the following structural formula (1) (hereinafter sometimes referred to as “precursor of xylan derivative”). It is a derivative and has a polystyrene (PS) equivalent number average molecular weight in the range of 3,000 to 150,000 measured by gel permeation chromatography (GPC) using an organic solvent.

<Raw material of precursor of xylan derivative>
The precursor of the xylan derivative may be produced using xylose, but it is present in large quantities in the natural world, for example, biomass such as wood, herbs, straw, bamboo, etc. Is preferred. Hereinafter, utilization of these biomass will be described using wood as an example.

<< Alkali extraction process >>
The wood is cut in advance and extracted with an aqueous sodium hydroxide solution of 5% by mass or more, preferably 16% by mass or more. The extraction time is preferably 10 hours or more, and more preferably 16 hours or more. The amount of the alkaline solution used is preferably 20 to 400 parts by mass, more preferably 100 to 320 parts by mass with respect to 100 parts by mass of the raw material.

<< pH adjustment process >>
After the alkali extraction step, the pH of the reaction solution is adjusted. The pH is preferably 5 to 8, and more preferably 6 to 7. As a reagent used for pH adjustment, acids such as hydrochloric acid, acetic acid and formic acid are preferable.

<< Precipitation process >>
After the pH adjustment step, a precipitation step is performed as necessary. This is to improve the recovery rate. In order to promote precipitation, for example, a lower alcohol such as ethanol or methanol is preferably added in a volume of 2 to 10 times, preferably 5 to 10 times the volume of the alkaline extract. Is more preferable.

<< Cleaning process >>
After the precipitation step, the obtained precipitate is washed with an organic solvent that can be easily removed, such as ethanol and methanol, as necessary, to remove unnecessary substances. Furthermore, removing unnecessary substances by filtration, centrifugation, etc. is effective from the viewpoint of avoiding the formation of by-products during the subsequent esterification reaction and etherification reaction.

<< Drying process >>
The precipitate obtained in the precipitation step or the washed precipitate obtained in the washing step is preferably dried in the drying step. There is no restriction | limiting in particular as said drying process, It performs by a freeze-drying method, a warm air drying method, a spray drying method, and a fluidized-bed drying method.

The “xylan derivative precursor” can be obtained by the above method.

<Manufacture of ester derivatives and ether derivatives of "precursor of xylan derivative">
<< Manufacture of nucleating agent >>
-Purpose and effect of esterification and etherification-
In the present invention, “a xylan derivative precursor” itself (xylan) is used as a nucleating agent. Alternatively, “a precursor of a xylan derivative” is esterified or etherified, that is, an ester derivative or an ether derivative is used as a nucleating agent. Esterification or etherification improves the affinity with crystalline polymer by converting the hydroxyl group in “precursor of xylan derivative” to ester group or ether group, and is good in crystalline polymer material. For the purpose of imparting a function as an excellent nucleating agent.
The degree of esterification and etherification is arbitrary, but at least until “the precursor of xylan derivative” which is insoluble in the organic solvent is dissolved in the organic solvent. Specifically, the molecular weight can be measured by gel permeation chromatography using an organic solvent.
Alternatively, etherification or esterification is performed until the hydroxyl group absorption intensity in the “precursor of xylan derivative” decreases by 50% or more with reference to the hydroxyl group absorption intensity of the IR spectrum.

-Methods of esterification and etherification-
A hydroxyl group in the “precursor of xylan derivative” has the same reactivity as a simple alcohol in the same manner as a hydroxyl group in xylose or a hydroxyl group in a sugar chain. The hydroxyl group of the “precursor of xylan derivative” exists in the sugar chain, but esterification or etherification proceeds relatively easily. Therefore, it is arbitrarily selected from reactions widely used in the field of synthetic organic chemistry. It's okay. The present inventors consider that the molecular weight of the “precursor of xylan derivative” is smaller than that of cellulose and the like, and that there are two hydroxyl groups and both are coordinated to equatorial.
In comparison between esterification reaction and etherification reaction, esterification generally proceeds under mild conditions with respect to carboxylic acid (including carboxylic anhydride and carboxylic acid chloride) and phosphoric acid. Is more preferable.

-Structure of ester and ether groups-
The structure of the ester group or ether group is not particularly limited, but from the viewpoint of easy reactivity with the “precursor of xylan derivative” and affinity with the crystalline polymer, a methyl group, an ethyl group, Alkyl groups such as propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group; alkanoyl groups such as acetyl group, propionyl group, hexanoyl group, decanoyl group, lauryl group; phenyl group; including benzyl group A structure is preferred.

-Molecular weight-
The molecular weight of the nucleating agent according to the present invention is a polystyrene-equivalent number average molecular weight measured by gel permeation chromatography (GPC), and is in the range of 3,000 to 150,000.
If it is less than 3,000, there is a problem in stability in the crystalline polymer, and if it exceeds 150,000, there is a problem in dispersion in the crystalline polymer material.
In the present invention, the polystyrene-equivalent number average molecular weight measured by the GPC method is a value obtained by measurement under the following conditions.
[Measurement condition]
Apparatus: Shimadzu 10A (manufactured by Shimadzu Corporation)
Column: Shodex (registered trademark) KG / 806K / 802 connection column (manufactured by Showa Denko KK)
Column temperature: 40 ° C
Moving layer: Chloroform Flow rate: 0.8 mL / min Apply: 50 μL

(Crystalline polymer composition)
The crystalline polymer composition according to the present invention includes a crystalline polymer and the above-described nucleating agent according to the present invention, so that a molding cycle at the time of processing accompanying an increase in the crystallization temperature during DSC temperature drop measurement It is a crystalline polymer composition that has been improved such as shortening.
The crystalline polymer composition containing at least the precursor of the xylan derivative and the crystalline polymer is also the crystalline polymer composition of the present invention.

<Crystalline polymer>
Examples of crystalline polymers include low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene resins (propylene homopolymers, propylene block copolymers, propylene random copolymers, and among these Isotactic, syndiotactic, (co) polymers having different atactic stereoregularity), polybutene-1, poly-3-methyl-1-butene, poly-3-methyl-1-pentene, Α-olefin polymers (polyolefin polymers) such as poly-4-methyl-1-pentene; aromatic polyester polymers such as polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate; polylactic acid polymers (for example, , Polylactic acid (poly-L-lactic acid, poly-D-lactic acid, stereo Complex polylactic acid), polycaprolactone, polyhydroxyalkanoate, etc.), polybutylene succinate and other biodegradable polyester polymers; poly-[(R) -3-hydroxybutyrate], poly-[(R ) -3-hydroxybutyrate-co- (R) -3-hydroxyhexanoate], poly-[(R) -3-hydroxybutyrate-co- (R) -4-hydroxybutyrate], poly- Examples include microorganism-produced polyester polymers such as [(R) -3-hydroxybutyrate-co- (R) -3-hydroxyvalerate].

<Addition amount>
In the crystalline polymer composition according to the present invention, one or more of the nucleating agents can be used as necessary, and the amount of each nucleating agent used is the crystalline polymer 100. The amount is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass with respect to parts by mass. If the amount is less than 0.01 parts by mass, the effect may not be obtained. If the amount exceeds 20 parts by mass, the characteristics of the crystalline polymer material itself may be lost.

<Addition method>
The method for adding the nucleating agent to the crystalline polymer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, (1) the crystalline polymer and the nucleating agent are A method of mixing (dry blending) each in a solid state (pellet, powder, etc.) and directly melt-molding it with a molding machine, (2) Melting and mixing the nucleating agent and the crystalline polymer in advance, A method of producing a mixture (masterbatch) containing a nucleating agent at a concentration higher than the concentration of the final composition, and adding the masterbatch to the crystalline polymer; and (3) the crystalline polymer. And the nucleating agent are mixed in advance by melt-kneading so as to obtain a final concentration, and a composition is produced, followed by molding. Further, these may be dissolved in a solvent capable of dissolving the crystalline polymer and the nucleating agent, and molded (solvent casting method) from the obtained solution.
In addition, in addition to the known nucleating agent, in addition to the known nucleating agent, antioxidant, weathering agent, antistatic agent, flame retardant, inorganic filler, organic filler, amorphous polymer, Elastomer, rubber, etc. may coexist.

Hereinafter, the present invention will be specifically described with reference to examples of the present invention, but the present invention is not limited to these examples.

(Preparation Example 1: Extraction of precursor of xylan derivative)
1 L of 10 mass% sodium hydroxide aqueous solution was added to 50 g of hardwood (eucalyptus kraft pulp, manufactured by Nippon Paper Industries Co., Ltd.), and alkali extraction was performed while stirring at 25 ° C. for 2 hours. Next, this was filtered using a filter paper (No. 1, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. Next, the extract was adjusted to pH 7.0 with acetic acid, 1 L of ethanol (purity 99%, manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto, and the mixture was allowed to stand at 25 ° C. for 12 hours. Next, the mixture was centrifuged at 10,000 rpm for 10 minutes, and xylan was recovered as a precipitate. Ethanol was added again to the precipitate, and the precipitate was washed by centrifugation under the same conditions. This washing was performed twice in total. Distilled water was added again to the precipitate, and the precipitate was washed by centrifugation under the same conditions. This washing was performed three times in total. The washed precipitate was dried overnight by freeze-drying to obtain 2.4 g of powdered hardwood xylan (precursor of xylan derivative). The yield was 4.8% by mass.

(Production Example 1: Synthesis of xylan acetate)
100 mg of xylan obtained in Preparation Example 1 was added to 2 mL of N, N-dimethylacetamide (DMAc, manufactured by Wako Pure Chemical Industries, Ltd.), and the mixture was stirred and mixed at 120 ° C. for 2 hours. The mixture was cooled to 100 ° C., 0.175 g of lithium chloride was added, and the mixture was cooled to room temperature (about 25 ° C.). Next, 0.24 mL of pyridine and 0.28 mL of acetic anhydride were added, and the mixture was stirred and mixed at 50 ° C. for 6 hours to carry out an esterification reaction.
The reaction solution after esterification is cooled to room temperature (about 25 ° C.), and charged into 100 mass% cold methanol (4 ° C.) of 5 times the amount of the reaction solution (about 10 mL), at 0.5 ° C. for 0.5 hour. After standing, xylan acetate was obtained as a precipitate by filtering with filter paper (No. 1, manufactured by Advantech Toyo Co., Ltd.). The yield was 86% by mass.

<Identification and confirmation of substitution degree>
Using a nuclear magnetic resonance apparatus (JNM-A500 FT-NMR, manufactured by JEOL), proton nuclear magnetic resonance ( ¹ H-NMR) of xylan acetate was measured in deuterated chloroform at 500 MHz. FIG. 1 shows the ¹ H-NMR spectrum of xylan acetate.
As shown in FIG. 1, a peak derived from CH ₃ appeared in the vicinity of 2 ppm, which is not present in xylan, and the presence of xylan acetate was confirmed.
Moreover, as a result of calculating the substitution degree (DS) of hydrogen atoms of two hydroxyl groups present in xylan from the integrated value of NMR, the substitution degree (DS) was 2.0.

<Molecular weight measurement>
10 mg of xylan acetate was suspended in 1 mL of chloroform, and the weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured by the gel permeation chromatography (GPC) method under the following measurement conditions. Mn and Mw were converted to polystyrene (PS).
As a result, the degree of polymerization (DP _n ) in xylan acetate is 179, the weight average molecular weight (Mw) is 69,000, the number average molecular weight (Mn) is 40,500, and Mw / Mn is 1.7.
[Measurement condition]
Apparatus: Shimadzu 10A (manufactured by Shimadzu Corporation)
Column: Shodex (registered trademark) KG / 806K / 802 connection column (manufactured by Showa Denko KK)
Column temperature: 40 ° C
Moving layer: Chloroform Flow rate: 0.8 mL / min Apply: 50 μL

<Measurement of 10% by mass pyrolysis temperature>
2 mg of xylan acetate was placed in a differential thermobalance (ThermoPlus DSC8320, manufactured by Rigaku Corporation), and the temperature was increased from 50 ° C. to 450 ° C. at 20 ° C./min in a nitrogen atmosphere. The 10% by mass thermal decomposition temperature determined from this TG curve was 304 ° C.
In addition, the 10 mass% thermal decomposition temperature of the xylan calculated | required by the same method was 217 degreeC.

(Production Example 2: Synthesis of xylampropionate)
In Production Example 1, xylanthropionate was obtained in the same manner as in Production Example 1, except that propionic anhydride was used instead of acetic anhydride and the esterification reaction time was changed to 6 hours to 36 hours. . The yield was 62% by mass.
Identification of the obtained xylampropionate, confirmation of the degree of substitution, measurement of molecular weight, and measurement of 10% by mass pyrolysis temperature were carried out in the same manner as in Production Example 1.

FIG. 2 shows the ¹ H-NMR spectrum of xylampropionate. From FIG. 2, the presence of xylampropionate was confirmed. Moreover, the substitution degree (DS) of hydrogen atoms of two hydroxyl groups present in xylan was 2.0.
Further, the degree of polymerization (DP _n ) in xylampropionate is 169, the weight average molecular weight (Mw) is 62,000, the number average molecular weight (Mn) is 41,300, and Mw / Mn Was 1.5, and the thermal decomposition temperature of 10% by mass was 296 ° C.

(Production Example 3: Synthesis of xylan hexanoate)
In Production Example 1, xylan hexanoate was obtained in the same manner as in Production Example 1, except that hexanoic anhydride was used instead of acetic anhydride and the esterification reaction time was changed to 6 hours to 48 hours. . The yield was 67% by mass.
Identification of the obtained xylan hexanoate, confirmation of the degree of substitution, measurement of molecular weight, and measurement of 10% by mass pyrolysis temperature were carried out in the same manner as in Production Example 1.

FIG. 3 shows the ¹ H-NMR spectrum of xylan hexanoate. From FIG. 3, the presence of xylan hexanoate was confirmed. Moreover, the substitution degree (DS) of hydrogen atoms of two hydroxyl groups present in xylan was 2.0.
The degree of polymerization (DP _n ) in xylan hexanoate is 132, the weight average molecular weight (Mw) is 65,000, the number average molecular weight (Mn) is 43,300, and Mw / Mn Was 1.5, and the thermal decomposition temperature of 10% by mass was 314 ° C.

(Production Example 4: Synthesis of xylan decanoate)
In Production Example 1, decanoic acid chloride was used in place of acetic anhydride, dimethylaminopyridine was used in place of pyridine, and the esterification reaction time was changed from 6 hours to 48 hours. In this way, xylan decanoate was obtained. The yield was 74% by mass.
The obtained xylan decanoate was identified, the degree of substitution was confirmed, the molecular weight was measured, and the 10% by mass pyrolysis temperature was measured in the same manner as in Production Example 1.

FIG. 4 shows the ¹ H-NMR spectrum of xylan decanoate. From FIG. 4, the presence of xylan decanoate was confirmed. Moreover, the substitution degree (DS) of hydrogen atoms of two hydroxyl groups present in xylan was 2.0.
The degree of polymerization (DP _n ) in xylan decanoate is 143, the weight average molecular weight (Mw) is 101,000, the number average molecular weight (Mn) is 63,100, and Mw / Mn Was 1.6, and the 10% by mass thermal decomposition temperature was 305 ° C.

(Production Example 5: Synthesis of xylan laurate)
In Production Example 1, lauric acid chloride was used instead of acetic anhydride, dimethylaminopyridine was used instead of pyridine, and the esterification reaction time was changed to 6 hours to 48 hours. Xylan laurate was obtained by the method. The yield was 73% by mass.
The obtained xylan laurate was identified, the degree of substitution was confirmed, the molecular weight was measured, and the 10% by mass pyrolysis temperature was measured in the same manner as in Production Example 1.

FIG. 5 shows a ¹ H-NMR spectrum of xylan laurate. From FIG. 5, the presence of xylan laurate was confirmed. Moreover, the substitution degree (DS) of hydrogen atoms of two hydroxyl groups present in xylan was 2.0.
The degree of polymerization (DP _n ) in xylan laurate is 123, the weight average molecular weight (Mw) is 98,000, the number average molecular weight (Mn) is 61,200, and Mw / Mn is 1.6, and the thermal decomposition temperature of 10% by mass was 295 ° C.

(Production Example 6: Synthesis of xylan butyrate)
In Production Example 1, xylan butyrate was obtained in the same manner as in Production Example 1, except that butanoic anhydride was used in place of acetic anhydride and the esterification reaction time was changed to 6 hours to 48 hours. The yield was 72% by mass.
Identification of the obtained xylan butyrate, confirmation of the degree of substitution, measurement of molecular weight, and measurement of 10% by mass pyrolysis temperature were carried out in the same manner as in Production Example 1.

FIG. 6 shows the ¹ H-NMR spectrum of xylan butyrate. From FIG. 6, the presence of xylan butyrate was confirmed. Moreover, the substitution degree (DS) of hydrogen atoms of two hydroxyl groups present in xylan was 2.0.
The degree of polymerization (DP _n ) in xylan butyrate is 170, the weight average molecular weight (Mw) is 73,000, the number average molecular weight (Mn) is 46,000, and Mw / Mn is 1.6, and the 10% by mass thermal decomposition temperature was 320 ° C.

(Production Example 7: Synthesis of xylan valerate)
In Production Example 1, valeric anhydride was used in place of acetic anhydride, and xylan valerate was obtained in the same manner as in Production Example 1, except that the esterification reaction time was changed to 6 hours to 48 hours. The yield was 73% by mass.
The obtained xylan valerate was identified, the degree of substitution was confirmed, the molecular weight was measured, and the 10% by mass pyrolysis temperature was measured in the same manner as in Production Example 1.

FIG. 7 shows a ¹ H-NMR spectrum of xylan valerate. From FIG. 7, the presence of xylan valerate was confirmed. Moreover, the substitution degree (DS) of hydrogen atoms of two hydroxyl groups present in xylan was 2.0.
In addition, the degree of polymerization (DP _n ) in xylan valerate is 156, the weight average molecular weight (Mw) is 77,000, the number average molecular weight (Mn) is 45,000, and Mw / Mn is 1.7, and the 10% by mass thermal decomposition temperature was 325 ° C.

(Examples 1 to 26: Preparation of solvent cast films F1 to F26)
Solvents shown in Table 1 below using the xylan derivatives of Production Examples 1 to 7 and poly-L-lactic acid (PLLA) represented by the following structural formula (A) by the following method Cast films F1 to F26 were produced.
0.5 g of poly-L-lactic acid (trade name: Lacty, manufactured by Shimadzu Corporation) is dissolved in 50 mL of chloroform, and each xylan derivative of Production Examples 1 to 7 is added to 100 parts by mass of poly-L-lactic acid. , 0.1 parts by weight, 0.5 parts by weight, 1 part by weight, 3 parts by weight, 5 parts by weight, and 10 parts by weight, and a completely dissolved mixture was prepared.
Each of these was poured into a Teflon (registered trademark) petri dish, covered with an appropriately perforated aluminum foil, dried in a fume hood (25 ° C.) for 12 hours, and the chloroform was volatilized. Examples 1-26 Solvent cast films F1 to F26 were prepared.

(Comparative Example 1: Production of solvent cast film F27)
In Examples 1 to 26, the same method as in Examples 1 to 26 except that poly-L-lactic acid (trade name: Lacty, manufactured by Shimadzu Corporation) was used without adding a xylan derivative. Solvent cast film F27 was produced.

(Examples 27 to 33: Production of solvent cast films F28 to 34)
Solvents shown in Table 1 below using the xylan derivatives of Production Examples 1 to 7 and poly-D-lactic acid (PDLA) represented by the following structural formula (B) by the following method Cast films F28 to F34 were produced.
PDLA (manufactured by Teijin Limited) 0.5 g was dissolved in chloroform 50 mL, and 1 part by mass of each xylan derivative of Production Examples 1 to 7 was mixed with 100 parts by mass of PDLA to prepare a completely dissolved mixture. did.
This was poured into a petri dish made of Teflon (registered trademark), covered with an appropriately perforated aluminum foil, dried in a fume hood (25 ° C.) for 12 hours to volatilize chloroform, and Examples 27-33 Solvent cast films F28 to 34 were prepared.

(Comparative Example 2: Production of solvent cast film F35)
In Examples 27 to 33, a solvent cast film F35 was produced in the same manner as in Examples 27 to 33 except that only the PDLA (manufactured by Teijin Limited) was used without adding the xylan derivative.

(Test Example 1: Evaluation of exothermic peak (Tc) and crystallization energy (ΔH) due to constant temperature increase)
Using the solvent cast film shown in Table 2 below, the exothermic peak (Tc) and crystallization energy (ΔH) were evaluated by the following crystallization method with a constant rate of temperature increase.
Each solvent cast film was put in an aluminum pan of a differential thermal balance (ThermoPlus DSC8320, manufactured by Rigaku Corporation), heated from room temperature to 200 ° C. at a heating rate of 20 ° C./min (first heating), The solvent cast film was completely dissolved. Next, after cooling to −50 ° C. at once with liquid nitrogen, the temperature was raised again at a rate of temperature rise of 20 ° C./min (second temperature rise).

FIG. 8A shows DSC curves at the second temperature rise of the solvent cast films F1, F5, F11, F15, F19, F23, and F27. FIG. 8B shows the solvent cast films F28 to 32, F34, and F35. The DSC curve at the time of a 2nd temperature rise is shown. Table 2 below collectively shows the results of the exothermic peak (Tc) and crystallization energy (ΔH) during the second temperature increase. 8A and 8B, “heat generation” is a change in relative heat flow, and the direction of heat generation is indicated by an arrow. It means that heat generation is positive in the direction of the arrow. The same meaning is shown in FIGS. 9A to 10F.

It can be confirmed from the crystallization exothermic peak (Tc) at the second temperature increase that the polymer compound (PLLA or PDLA in this case) has been crystallized by the crystallization method by the constant temperature increase. In the crystallization method based on the constant rate of temperature increase, the lower the temperature of the exothermic peak (Tc) at the second temperature increase, the easier it is to crystallize. Furthermore, the larger the absolute value of the crystallization energy (ΔH) obtained from the peak area of the exothermic peak (Tc) at the second temperature rise, the higher the crystallinity in the crystalline polymer composition.
From the results shown in FIGS. 8A and 8B and Table 2, in the solvent cast film F27 made of poly-L-lactic acid, an exothermic peak (Tc) derived from crystallization was observed at 120 ° C., and the solvent made of poly-D-lactic acid. In the cast film F35, an exothermic peak (Tc) derived from crystallization was observed at 119 ° C.
In contrast, in the solvent cast films F1, F5, F11, F15, F19, F23, F28 to 32, and F34 to which the xylan derivative was added, the position of the exothermic peak (Tc) was shifted to the low temperature side. Thereby, it was confirmed that the xylan derivative functions as a nucleating agent. In particular, the position of the exothermic peak (Tc) is shifted to 93 ° C. for xylampropionate, and the position of the exothermic peak (Tc) is shifted to 97 ° C. for xylan butyrate. In particular, its function was excellent. In addition, here, PLLA or PDLA was used as a polymer compound, and an effect as a nucleating agent for a xylan derivative was observed. However, the xylan derivative has a function as a nucleating agent for both PLLA and PDLA. Therefore, it is inferred that the xylan derivative also functions as a nucleating agent for stereocomplex polylactic acid, which is a complex composed of PLLA and PDLA.

FIG. 9A shows a DSC curve during the second temperature rise of the solvent cast films F5 to 8 and F27, and FIG. 9B shows a DSC curve during the second temperature rise of the solvent cast films F9 to 13 and F27. . 9A and 9B, when the addition amount of the xylan derivative was changed, any addition amount had an excellent function as a nucleating agent. Moreover, it turned out that the outstanding nucleation effect | action can be obtained by addition of a small amount of 0.1 mass part of xylan derivatives with respect to 100 mass parts of high molecular compounds.

(Test Example 2: Evaluation of exothermic peak (Tc) and crystallization energy (ΔH) due to constant temperature drop)
Using the solvent cast film shown in Table 3 below, the exothermic peak (Tc) and the crystallization energy (ΔH) were evaluated by the crystallization method based on the constant temperature drop shown below.
Each solvent cast film was put in an aluminum pan of a differential thermal balance (ThermoPlus DSC8320, manufactured by Rigaku Corporation) and heated from room temperature to 200 ° C. at a heating rate of 20 ° C./minute to completely dissolve each solvent cast film. . Subsequently, the temperature was decreased at a rate of temperature decrease of 2 ° C./min, 5 ° C./min, 10 ° C./min, or 20 ° C./min.

FIG. 10A shows a DSC curve when the solvent cast film F5 is lowered, FIG. 10B shows a DSC curve when the solvent cast film F11 is lowered, FIG. 10C shows a DSC curve when the solvent cast film F27 is lowered, and FIG. 10D shows a solvent. The DSC curve when the cast film F29 cools down, FIG. 10E shows the DSC curve when the solvent cast film F30 cools down, and FIG. 10F shows the DSC curve when the solvent cast film F35 cools down. Table 3 below summarizes the results of the exothermic peak (Tc) and crystallization energy (ΔH) when the temperature is lowered.

It can be confirmed from the exothermic peak (Tc) of crystallization at the time of the temperature decrease that the polymer compound (here, PLLA or PDLA) is crystallized by the crystallization method by the constant temperature decrease. In the constant-speed temperature-falling crystallization, the higher the temperature of the exothermic peak (Tc) at the time of temperature-falling, the easier the crystallization.
From the results of FIGS. 10A to 10F and Table 3, when the temperature was lowered at 2 ° C./minute in the solvent cast film F27, only a small crystallization energy (ΔH) was observed at an exothermic peak (Tc) of 104 ° C., and the solvent cast film F27 No exothermic peak (Tc) was observed when the temperature was lowered at 20 ° C./min. This result is similar in the solvent cast film F35, and no exothermic peak (Tc) was observed in the solvent cast film F35 when the temperature was lowered at 20 ° C./min.
In contrast, in the solvent cast films F5, F11, F29, and F30 to which the xylan derivative was added, an exothermic peak (Tc) and a large crystallization energy (ΔH) were observed at any temperature decreasing rate. From this, it was confirmed that the xylan derivative functions as a nucleating agent.

(Test Example 3: Evaluation of half-crystallization time (t _1/2 ), crystallinity, haze value, and thermal expansion coefficient)
Using the solvent cast film shown in Table 4 below, crystallization was performed by the isothermal crystallization method shown below.
Each solvent cast film was put in an aluminum pan of a differential thermal balance (ThermoPlus DSC8320, manufactured by Rigaku Corporation) and heated from room temperature to 200 ° C. at a heating rate of 20 ° C./min to completely melt each solvent cast film. . Subsequently, it cooled to 100 degreeC, 110 degreeC, 120 degreeC, or 130 degreeC, and hold | maintained (annealing) until it crystallized at each temperature.

<Evaluation of semi-crystallization time (t _1/2 )>
The half crystallization time (t1 _{/ 2} ) of each solvent cast film at the time of heat retention was calculated | required by the time of the half value width of the exothermic peak. The results are shown in Table 4 below.

The crystallization of the polymer compound (here, PLLA or PDLA) by the isothermal crystallization method can be confirmed by the crystallization exothermic peak (Tc) during temperature holding, and the half crystallization time (t _1/2 ) Indicates that the crystallization is easier as the length is shorter. From the results of Table 4, the solvent cast films F5, F11, F29, and F30 to which the xylan derivative is added are compared with the solvent cast films F27 and F35 made of PLLA or PDLA. It was confirmed that the half crystallization time (t _1/2 ) was significantly shortened at any temperature.
FIG. 11A shows the results of observing the solvent cast films F5, F11, and F27 kept at 100 ° C. or 130 ° C. with a polarizing microscope, and FIG. 11B shows the solvent cast films F29, F30, and F35 kept at 100 ° C. or 130 ° C. The result observed with the polarization microscope is shown.
From FIG. 11A and FIG. 11B, it is clear that the solvent cast films F5, F11, F29, and F30 to which the xylan derivative is added have smaller crystals and more than the solvent cast films F27 and F35 made of PLLA or PDLA. Met. From these results, it was confirmed that the xylan derivative functions as a nucleating agent.

<Evaluation of crystallinity>
In the evaluation of the half crystallization time (t _1/2 ), the relationship between the annealing time and the crystallinity when kept at 100 ° C. (annealing) was examined.
Here, the degree of crystallinity (%) was measured with a wide-angle X-ray measurement apparatus (RINT2000, manufactured by Rigaku Corporation).

Figure 12 shows the results. From FIG. 12, the crystallization degree increased with time in any of the solvent cast films F5, F11, and F27, but the solvent cast film F5 to which the xylan derivative was added as compared with the solvent cast film F27 of PLLA alone. In F11 and F11, crystallization was promoted, and a higher crystallinity was reached in a short time.

<Evaluation of haze value>
In the evaluation of the half crystallization time (t _1/2 ), the relationship between the annealing time and the haze value when kept at 100 ° C. (annealing) was examined.
Here, the haze value (%) was measured with a haze meter (HZ-V3, manufactured by Suga Test Instruments Co., Ltd.). The haze value indicates the haze of the film, and the smaller the value, the higher the transparency.

Fig. 13 shows the results. From FIG. 13, the solvent cast films F5 and F11 to which the xylan derivative is added maintain high transparency even when the heat treatment time (annealing time) is long, that is, even when the crystallinity is high. It was. FIG. 14 shows photographs of the solvent cast films F5, F11, and F27 after 10 minutes at 100 ° C. This is because the crystals are very small, as can be seen from the results in FIGS. 11A and 11B.

<Evaluation of thermal expansion coefficient>
In the evaluation of the half crystallization time (t _1/2 ), the relationship between the annealing time and the thermal expansion when kept at 100 ° C. (annealing) was examined.
Here, the coefficient of thermal expansion (%) was measured with a thermomechanical measuring device (TMA-60, manufactured by Shimadzu Corporation).

Fig. 15 shows the results. In all the samples not subjected to heat treatment, thermal expansion of 14% or more occurred at 100 ° C. However, when xylan derivative was added and heat treatment was performed for several minutes, thermal expansion was suppressed to about 1%.

(Example 34: Production and thermal analysis of hot press film)
Production example for 100 parts by mass (30 g) of polypropylene (PP) (density 0.90, melt flow rate (MFR) 1.0 at 230 ° C./2.16 kg load, trade name: PL300A, manufactured by Sun Allomer Co., Ltd.) 5 xylan laurate 0.03 parts by mass (0.08 g) and 1 part by mass (0.3 g) of dibutylhydroxytoluene (BHT) were mixed and melt kneaded at 230 ° C. for 1 minute in a plastograph melt kneader. . The molten resin was scraped from the plastograph, and a hot press film F36 was produced using a hot press at 230 ° C.

The hot press film F36 was put into an aluminum pan of a differential thermal balance (ThermoPlus DSC8320, manufactured by Rigaku Corporation), and the temperature was raised from room temperature to 200 ° C. at a heating rate of 10 ° C./min to completely dissolve the hot press film F36. . After maintaining at 200 ° C. for 5 minutes, the temperature was decreased to 20 ° C. at a temperature decrease rate of 20 ° C./min. Further, the melting point (Tm) was determined from the crystal from the tangent line of the endothermic peak when the temperature was raised from 20 ° C. to 200 ° C. at 10 ° C./min. The endothermic peak was divided by the charged weight to determine the melting energy. The results are shown in Table 5 below.

(Example 35: Production and thermal analysis of hot press film)
In Example 34, except that 0.03 parts by mass (0.08 g) of xylan of Preparation Example 1 was used instead of 0.03 parts by mass (0.08 g) of xylan laurate during the melt kneading of PP. Produced a hot press film F37 in the same manner as in Example 34, and conducted thermal analysis in the same manner as in Example 34. The results are shown in Table 5 below.

(Comparative Example 3: Production and thermal analysis of hot press film)
In Example 34, except that xylan laurate was not used in the melt-kneading of PP, a hot press film F38 was produced in the same manner as in Example 34, and thermal analysis was conducted in the same manner as in Example 34. Went. The results are shown in Table 5 below.

From the results of Table 5, it was clear that in Examples 34 and 35, the melting point and melting energy were higher and the crystallinity was improved as compared with Comparative Example 3.

These Examples and Test Examples From these results, it was confirmed that xylan (a precursor of xylan derivatives) and xylan derivatives have an action as a nucleating agent.

Claims (15)

1. A derivative obtained by esterification or etherification of xylan having a repeating structural unit represented by the following structural formula (1):
   A crystalline polymer nucleating agent having a polystyrene-equivalent number average molecular weight measured by gel permeation chromatography in a range of 3,000 to 150,000.
   

   
2. A derivative obtained by esterification of xylan having a repeating structural unit represented by the following structural formula (1):
   A crystalline polymer nucleating agent having a polystyrene-equivalent number average molecular weight measured by gel permeation chromatography in a range of 3,000 to 150,000.
   

   
3. A derivative obtained by esterifying xylan having a repeating structural unit represented by the following structural formula (1) with an alkanoyl group having 2 to 12 carbon atoms;
   A crystalline polymer nucleating agent having a polystyrene-equivalent number average molecular weight measured by gel permeation chromatography in a range of 3,000 to 150,000.
   

   
4. A crystalline polymer composition comprising the crystalline polymer nucleating agent according to any one of claims 1 to 3.
5. The crystalline polymer composition according to claim 4, wherein the crystalline polymer is a biodegradable polyester polymer.
6. The crystalline polymer composition according to claim 4, wherein the crystalline polymer is a polylactic acid polymer.
7. The crystalline polymer composition according to claim 4, wherein the crystalline polymer is a microorganism-produced polyester polymer.
8. The crystalline polymer composition according to claim 4, wherein the crystalline polymer is a polyolefin polymer.
9. The crystalline polymer composition according to claim 4, wherein the crystalline polymer is a polypropylene resin.
10. A crystalline polymer composition comprising the xylan derivative precursor according to any one of claims 1 to 3.
11. The crystalline polymer composition according to claim 10, wherein the crystalline polymer is a biodegradable polyester polymer.
12. The crystalline polymer composition according to claim 10, wherein the crystalline polymer is a polylactic acid polymer.
13. The crystalline polymer composition according to claim 10, wherein the crystalline polymer is a microorganism-produced polyester polymer.
14. The crystalline polymer composition according to claim 10, wherein the crystalline polymer is a polyolefin polymer.
15. The crystalline polymer composition according to claim 10, wherein the crystalline polymer is a polypropylene resin.

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