阅读说明：本技术 聚缩醛树脂组合物和聚缩醛树脂组合物的制造方法 (Polyacetal resin composition and method for producing polyacetal resin composition ) 是由 喜来直裕 增田荣次 于 2019-12-05 设计创作，主要内容包括：本发明的目的在于,提供改善了机械物性的水平的聚缩醛树脂组合物。本发明通过如下聚缩醛树脂组合物实现：其是相对于聚缩醛树脂(A)100质量份混合至少使三氧杂环己烷(a)、式(1)所示的硅氧烷化合物(b)共聚而得到的聚缩醛共聚物(B)0.1～100质量份而得到的。(式(1)中,分别地R～1表示碳数1～6的一价脂肪族烃基或碳数6～10的芳香族烃基,X表示R～1或具有环氧基的有机基团。其中存在多个的X中的2个以上为具有环氧基的有机基团,存在多个的R～1、X任选分别相同或不同。)(The invention aims to provide a polyacetal resin composition with improved mechanical property level. The present invention is realized by the following polyacetal resin composition: the resin composition is obtained by mixing 0.1-100 parts by mass of a polyacetal copolymer (B) obtained by copolymerizing at least trioxane (a) and a siloxane compound (B) represented by the formula (1) with 100 parts by mass of a polyacetal resin (A). (in the formula (1), R is each 1 Represents a C1-6 monovalent aliphatic hydrocarbon group or C6-10 aromatic hydrocarbon group, X represents R 1 Or an organic group having an epoxy group. It is composed ofWherein at least 2 of X's are organic groups having epoxy groups and at least R's are present 1 And X are optionally the same or different. ))

1. A polyacetal resin composition obtained by mixing 0.1 to 100 parts by mass of a polyacetal copolymer (B) obtained by copolymerizing at least trioxane (a) and a siloxane compound (B) represented by the formula (1) with 100 parts by mass of a polyacetal resin (A),

in the formula (1), R is independently¹Represents a C1-6 monovalent aliphatic hydrocarbon group or C6-10 aromatic hydrocarbon group, X represents R¹Or an organic group having an epoxy group, wherein 2 or more of X's in the plural are organic groups having an epoxy group, and R's in the plural are present¹And X are optionally the same or different.

2. The polyacetal resin composition according to claim 1, wherein the copolymer (B) is a polyacetal copolymer (B) obtained by copolymerizing, as a comonomer, a cyclic acetal compound (c) having an oxyalkylene group having at least 2 carbon atoms in the ring.

3. The polyacetal resin composition according to claim 1 or 2, wherein the organic group having an epoxy group in the siloxane compound (b) represented by the formula (1) is a 2- (3, 4-cyclohexyl) ethyl group.

4. The polyacetal resin composition according to any one of claims 1 to 3, wherein the siloxane compound (b) represented by the formula (1) is a compound (b-1) wherein Me represents a methyl group,

5. the polyacetal resin composition according to any one of claims 1 to 4, wherein the polyacetal resin (A) is an acetal copolymer.

6. A method for producing a polyacetal resin composition, wherein the polyacetal resin composition is obtained by mixing 0.1-100 parts by mass of a polyacetal copolymer (B) obtained by copolymerizing at least trioxane (a) and a siloxane compound (B) represented by the formula (1) with 100 parts by mass of a polyacetal resin (A),

in the formula (1), R is independently¹Represents a C1-6 monovalent aliphatic hydrocarbon group or C6-10 aromatic hydrocarbon group, X represents R¹Or an organic group having an epoxy group, wherein 2 or more of X's in the plural are organic groups having an epoxy group, and R's in the plural are present¹And X are optionally the same or different.

Technical Field

The present invention relates to a polyacetal resin composition having excellent mechanical properties and a method for producing the polyacetal resin composition.

Background

Polyacetal resins have excellent properties in terms of mechanical properties, thermal properties, electrical properties, slidability, moldability and the like, and are widely used mainly as structural materials, mechanical parts and the like for electrical equipment, automobile parts, precision machine parts and the like. However, as the field of application of polyacetal resins has expanded, the required properties have tended to be increasingly higher, more complex and more specialized. As such required properties, improvement in rigidity and suppression of formaldehyde generation are required while maintaining excellent sliding properties and appearance which polyacetal resins originally have.

On the other hand, for the purpose of improving the rigidity, a method of filling a fibrous filler or the like into a polyacetal resin is generally used, but this method has problems such as poor appearance of a molded article, reduction in sliding characteristics, and the like due to filling of the fibrous filler or the like, and further has a problem of reduction in toughness.

Further, it is known that the rigidity of the polyacetal copolymer is improved without substantially impairing the slidability and the appearance by reducing the amount of the comonomer, but the method of reducing the comonomer causes problems such as not only a decrease in toughness but also a decrease in thermal stability of the polymer, and thus the method is not always satisfactory.

Further, an attempt has been made to improve rigidity by blending a polyacetal copolymer having a branched structure introduced thereinto (patent document 1), but when a polyacetal copolymer having a branched structure introduced thereinto is polymerized, initiation of polymerization may be delayed depending on the kind of a comonomer, and when a cationic polymerization catalyst, particularly protonic acid, is used as a polymerization catalyst, polymerization may suddenly and explosively occur, and there is a problem in view of production stability.

For example, as for the polyacetal copolymer, a copolymer obtained by copolymerizing trioxane with a compound having 2 or more glycidyl ether groups in 1 molecule has been proposed (patent document 2). However, when a compound having a plurality of epoxy groups represented by glycidyl ether groups and ether oxygen groups as functional groups is used in polymerization, there remains a problem in polymerization stability. In particular, when a protonic acid is used as a polymerization catalyst, polymerization does not occur at a low catalyst amount, and when the catalyst amount is increased, a phenomenon occurs in which a sharp polymerization reaction suddenly occurs after an irregular induction period, and it is difficult to control the polymerization.

Documents of the prior art

Patent document

Patent document 1: japanese examined patent publication No. 55-019942

Patent document 2: japanese laid-open patent application No. 2001-163944

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide a polyacetal resin composition with improved mechanical property and a method for producing the polyacetal resin composition.

Means for solving the problems

The present inventors have intensively studied to achieve the above object and, as a result, found that: a polyacetal copolymer obtained by copolymerizing a trioxane and a specific siloxane compound with a polyacetal resin as a base can improve mechanical properties which have been unexpected so far, and the present invention has been completed.

1. A polyacetal resin composition obtained by mixing 0.1 to 100 parts by mass of a polyacetal copolymer (B) obtained by copolymerizing at least trioxane (a) and a siloxane compound (B) represented by the formula (1) with 100 parts by mass of a polyacetal resin (A).

(in the formula (1), R is each¹Represents a C1-6 monovalent aliphatic hydrocarbon group or C6-10 aromatic hydrocarbon group, X represents R¹Or an organic group having an epoxy group. Wherein 2 or more of X's in the plural are organic groups having an epoxy group, and R's in the plural are present¹And X are optionally the same or different. )

2. The polyacetal resin composition according to claim 1, wherein the copolymer (B) is a polyacetal copolymer (B) obtained by copolymerizing, as a comonomer, a cyclic acetal compound (c) having an oxyalkylene group having at least 2 carbon atoms in the ring.

3. The polyacetal resin composition according to 1 or 2, wherein the organic group having an epoxy group in the siloxane compound (b) represented by the formula (1) is a 2- (3, 4-cyclohexyl) ethyl group.

4. The polyacetal resin composition according to any one of the preceding 1 to 3, wherein the siloxane compound (b) represented by the formula (1) is the following compound (b-1). In the formula (b-1), Me represents a methyl group.

5. The polyacetal resin composition according to any one of the preceding 1 to 4, wherein the polyacetal resin (A) is an acetal copolymer.

6. A method for producing a polyacetal resin composition, wherein the polyacetal resin composition is obtained by mixing 0.1-100 parts by mass of a polyacetal copolymer (B) obtained by copolymerizing at least trioxane (a) and a siloxane compound (B) represented by the formula (1) with 100 parts by mass of a polyacetal resin (A).

(in the formula (1), R is each¹Represents a C1-6 monovalent aliphatic hydrocarbon group orAn aromatic hydrocarbon group having 6 to 10 carbon atoms, X represents R¹Or an organic group having an epoxy group. Wherein 2 or more of X's in the plural are organic groups having an epoxy group, and R's in the plural are present¹And X are optionally the same or different. )

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided a polyacetal resin composition having improved mechanical properties and a method for producing the polyacetal resin composition.

Detailed Description

The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the intended scope of the present invention.

< polyacetal resin composition >

The polyacetal resin composition of the present invention is characterized by comprising: a polyacetal resin (A) and a polyacetal copolymer (B) obtained by copolymerizing trioxane (a), a siloxane compound (B) represented by the formula (1) and, in some cases, a cyclic acetal compound (c) having an oxyalkylene group having 2 or more carbon atoms in the ring,

(in the formula (1), R is each¹Represents a C1-6 monovalent aliphatic hydrocarbon group or C6-10 aromatic hydrocarbon group, X represents R¹Or an organic group having an epoxy group. Wherein 2 or more of X's in the plural are organic groups having an epoxy group, and R's in the plural are present¹And X are optionally the same or different. ).

In the resin composition of the present invention, the amount of the polyacetal copolymer (B) to be blended is 0.1 to 100 parts by mass, preferably 0.3 to 100 parts by mass, based on 100 parts by mass of the polyacetal resin (a).

< polyacetal resin (A) >)

The configuration of the polyacetal resin composition of the present invention will be described in detail below.

The polyacetal resin (a) as the matrix of the resin composition of the present invention means: with oxymethylene units (-CH)₂O-) is a main structural unit, comprising: acetal homopolymers (e.g., product name "Delrin" manufactured by DuPont inc., U.S. and the like) and acetal copolymers containing comonomer units in addition to oxymethylene groups (e.g., polymer plastics co., product name "Duracon" manufactured by ltd., and the like).

The polyacetal resin (a) blended in the present invention is particularly preferably an acetal copolymer in terms of thermal stability and the like.

In the acetal copolymer, the comonomer unit contains oxyalkylene units having about 2 to 6 carbon atoms (preferably about 2 to 4 carbon atoms) (for example, oxyethylene (-CH)₂CH₂O-), oxypropylene, oxybutylene, etc.).

The content of the comonomer unit is an amount not significantly impairing the crystallinity of the resin, and may be selected from the range of usually 0.01 to 20 mol%, preferably 0.03 to 10 mol%, and more preferably 0.1 to 7 mol%, in terms of the ratio of the comonomer unit in the structural unit of the polyacetal polymer.

The acetal copolymer may be a copolymer composed of two components, a terpolymer composed of three components, or the like. In addition to random copolymers, the acetal copolymers may also be block copolymers, graft copolymers, and the like.

The polymerization degree, branching degree and crosslinking degree of the polyacetal resin (a) are not particularly limited, so long as the polyacetal resin (a) can be melt-molded.

< polyacetal copolymer (B) >)

The polyacetal copolymer (B) of the present invention is a polyacetal copolymer (B) obtained by copolymerizing trioxane (a), a siloxane compound (B) represented by the formula (1), and optionally a cyclic acetal compound (c) having an oxyalkylene group having 2 or more carbon atoms in the ring,

(formula (I))1) In (1), respectively R¹Represents a C1-6 monovalent aliphatic hydrocarbon group or C6-10 aromatic hydrocarbon group, X represents R¹Or an organic group having an epoxy group. Wherein 2 or more of X's in the plural are organic groups having an epoxy group, and R's in the plural are present¹And X are optionally the same or different. ).

Trioxane (a)

Trioxane used in the present invention is a cyclic trimer of formaldehyde, and is generally obtained by reacting an aqueous formaldehyde solution in the presence of an acidic catalyst, and is used by purifying it by a method such as distillation.

A siloxane compound (b) represented by the formula (1)

The component (b) used in the present invention is characterized by being a siloxane compound represented by the formula (1).

(in the formula (1), R is each¹Represents a C1-6 monovalent aliphatic hydrocarbon group or C6-10 aromatic hydrocarbon group, X represents R¹Or an organic group having an epoxy group. Wherein 2 or more of X's in the plural are organic groups having an epoxy group, and R's in the plural are present¹And X are optionally the same or different. )

R¹Examples of the monovalent aliphatic hydrocarbon group include a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms, and include a saturated monovalent aliphatic hydrocarbon group such as an alkyl group such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, heptyl group, etc., an unsaturated monovalent aliphatic hydrocarbon group such as an alkenyl group such as a vinyl group, allyl group, isopropenyl group, butenyl group, etc., a phenyl group, naphthyl group, etc., preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group.

The organic group in X is a compound formed of C, H, N, O atoms, specific examples of the epoxy group-containing organic group include a 2- (3, 4-cyclohexyl) ethyl group and a 3-glycidoxypropyl group, and a 2- (3, 4-cyclohexyl) ethyl group is preferable from the viewpoint of stability of the polymerization reaction. Here, the number of carbon atoms in the organic group is preferably 1 to 20, more preferably 3 to 15. From the viewpoint of stability of polymerization and mechanical strength, a 2- (3, 4-cyclohexyl) ethyl group via an alkylene group having 1 to 5 carbon atoms is preferable.

The siloxane compound of the formula (1) can be produced by a known method described in, for example, Japanese patent application laid-open Nos. 2010-229324 and 2016-204288. When these production methods are applied, a cyclic siloxane having a 6-membered ring, a 10-membered ring or a 12-membered ring in which 3, 5 or 6 units of siloxane units are bonded may be formed as a by-product, but the presence of these units has little influence on the production of the polyacetal copolymer of the present invention, and it is sufficient if the cyclic siloxane having an 8-membered ring of the present invention is contained in an amount of 80% by mass or more.

The reason why the polymerization control is facilitated when the siloxane compound of formula (1) is copolymerized in the present invention is presumably because the epoxy group serving as a copolymerization reaction site is fixed to the outside of the molecule by the siloxane ring structure of formula (1), and thus the reaction probability is increased.

Particularly preferred silicone compounds are the following compounds (b-1). In the formula (b-1), Me represents a methyl group.

In the present invention, the component (b) is preferably used in an amount within a range of 0.01 to 5 parts by mass, more preferably 0.03 to 1 part by mass, based on 100 parts by mass of trioxane.

Cyclic acetal compound (c) having oxyalkylene group having 2 or more carbon atoms in the ring

In the polyacetal copolymer (B) of the present invention, the cyclic acetal compound (c) having an oxyalkylene group having 2 or more carbon atoms in the ring may be further used as a comonomer.

The cyclic acetal compound having an oxyalkylene group having 2 or more carbon atoms in the ring according to the present invention means: specific examples of the compound generally used as a comonomer in the production of the polyacetal copolymer include 1, 3-dioxolane, 1,3, 6-trioxane, 1, 4-butanediol formal, and the like.

In the present invention, the component (c) is preferably used in an amount within a range of 0.01 to 20 parts by mass, and more preferably 0.05 to 5 parts by mass, based on 100 parts by mass of trioxane.

< method for producing polyacetal copolymer (B) >

The method for producing the polyacetal copolymer (B) of the present invention is characterized by copolymerizing trioxane (a) and a specific cyclic siloxane compound (B) having 2 or more epoxy groups in the molecule, which is represented by the formula (1), in the presence of a cationic polymerization catalyst.

< cationic polymerization catalyst >

As the cationic polymerization catalyst, a polymerization catalyst known for cationic copolymerization using trioxane as a main monomer can be used. Typical examples thereof include protonic acids and Lewis acids.

Proton acid

Examples of the protonic acid include perfluoroalkanesulfonic acid, heteropolyacid, and isopoly acid.

Specific examples of perfluoroalkanesulfonic acids include trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid, nonafluorobutanesulfonic acid, undecafluoropentanesulfonic acid, tridecafluorohexanesulfonic acid, pentadecafluoroheptanesulfonic acid, and heptadecafluorooctanesulfonic acid.

The heteropoly acid is a polyacid produced by dehydration condensation of various kinds of oxo acids, and has a single-core or multi-core complex ion in which a specific different element is present in the center and an oxygen atom is shared to enable condensation of a condensed acid group. Isopoly acids, also known as isopoly acids, homonuclear condensation acids, isopoly acids, refer to high molecular weight inorganic oxoacids formed from the condensation of inorganic oxoacids of a single type of metal having a valence of V or VI.

Specific examples of the heteropoly-acid include phosphomolybdic acid, phosphotungstic acid, phosphomolybdotungstic acid, phosphomolybdovanadic acid, phosphomolybdotungstovanadic acid, phosphotungstovanadic acid, silicotungstic acid, silicomolybdic acid, silicomolybdotungstic acid, silicomolybdotungstovanadic acid, and the like. In particular, the heteropoly-acid is preferably selected from the group consisting of silicomolybdic acid, silicotungstic acid, phosphomolybdic acid, phosphotungstic acid, from the viewpoint of polymerization activity.

Specific examples of the isopoly acid include tungsten isopoly acids exemplified by paratungstic acid, metatungstic acid, and the like; molybdenum isopolyacids exemplified by paramolybdic acid, metamolybdic acid, and the like; metavanadate, vanadium isopoly acid, and the like. Among them, tungsten isopoly acid is preferable from the viewpoint of polymerization activity.

Lewis acid

Examples of the lewis acid include halides of boron, tin, titanium, phosphorus, arsenic and antimony, and specifically, boron trifluoride (and its ether complex), tin tetrachloride, titanium tetrachloride, phosphorus pentafluoride, phosphorus pentachloride, antimony pentafluoride, and complexes or salts thereof.

The amount of the polymerization catalyst is not particularly limited, but is preferably 0.1ppm to 50ppm, more preferably 0.1ppm to 30ppm, based on the total amount of all monomers.

In the production of the polyacetal copolymer (B) of the present invention, the amount of the terminal group may be adjusted by using a component for adjusting the molecular weight in combination with the above-mentioned component. Examples of the component for adjusting the molecular weight include compounds having an alkoxy group such as methylal, monomethoxymethylal, dimethoxymethylal, which are chain transfer agents not forming an unstable terminal.

The method for producing the polyacetal copolymer (B) of the present invention is not particularly limited. The polymerization apparatus is not particularly limited during the production, and any known apparatus, such as a batch type or a continuous type, may be used. Further, the polymerization temperature is preferably maintained at 65 ℃ or higher and 135 ℃ or lower.

The cationic polymerization catalyst is preferably used by diluting with an inactive solvent which does not adversely affect the polymerization. The deactivation of the polymerization catalyst after the polymerization can be carried out by a conventionally known method. For example, the polymerization may be carried out by adding a basic compound or an aqueous solution thereof to the reaction product discharged from the polymerization reactor or the reaction product in the polymerization reactor after the polymerization reaction.

The basic compound used for neutralizing and deactivating the polymerization catalyst is not particularly limited. After polymerization and deactivation, washing, separation and recovery of unreacted monomers, drying, and the like are further performed by a conventionally known method as needed.

The polyacetal copolymer obtained as described above preferably has a weight average molecular weight corresponding to methyl methacrylate determined by size exclusion chromatography of 10000 to 500000, particularly 20000 to 150000. In addition, for the terminal groups, from¹The amount of the terminal group of the hemiformal to be detected by H-NMR (for example, according to the method described in Japanese patent application laid-open No. 2001-11143) is preferably 0 to 4mmol/kg, and particularly preferably 0 to 2 mmol/kg.

In order to control the hemiformal end group content within the above range, impurities, particularly water, in the total amount of monomers and comonomers to be polymerized are preferably 20ppm or less, and particularly preferably 10ppm or less.

< other ingredients >

The resin composition of the present invention is preferably blended with various known stabilizers selected as needed. The stabilizer used here may be any one of 1 or 2 or more of hindered phenol compounds, nitrogen-containing compounds, hydroxides, inorganic salts, and carboxylates of alkali metals or alkaline earth metals.

Further, if necessary, 1 or 2 or more of additives commonly used for thermoplastic resins, for example, weather (light) -resistant stabilizers, colorants such as dyes and pigments, lubricants, nucleating agents, mold release agents, antistatic agents, surfactants, or organic polymer materials, inorganic or organic fibrous, powdery, and plate-like fillers may be added as long as the present invention is not hindered.

< method for producing polyacetal resin composition >

In order to produce the polyacetal resin composition of the present invention, a melt-kneading apparatus is used. The melt-kneading apparatus is not particularly limited, and has a function of kneading the polyacetal resin and the polyacetal copolymer after melting, and preferably has a function of exhausting gas, and examples thereof include a single-screw or multi-screw continuous extrusion kneader having at least 1 exhaust hole, a co-kneader, and the like. The melt-kneading treatment is preferably carried out at a temperature in the range of 260 ℃ or higher than the melting point of the polyacetal resin and the polyacetal copolymer. If the temperature is higher than 260 ℃, decomposition and deterioration of the polymer occur, which is not preferable.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

The polyacetal resins (a) and polyacetal copolymers (B) used in the examples and comparative examples are as follows.

< polyacetal resin (A) >)

The polyacetal resin (A) was prepared as follows.

A mixture of Trioxane (TOX) 96.7% by mass, 1, 3-Dioxolane (DO) 3.3% by mass and methylal 800ppm was continuously fed into a twin-screw continuous polymerization reactor, and boron trifluoride dibutyl ether complex (dibutyl ether solution) 20ppm (in terms of boron trifluoride) was added as a catalyst to conduct polymerization.

The polymer discharged from the outlet of the polymerization reactor was immediately added with an aqueous solution containing 1000ppm of triethylamine, and the mixture was pulverized and stirred to deactivate the catalyst. Subsequently, the polymer was recovered by centrifugal separation and dried to obtain a polyacetal resin (a).

< polyacetal copolymer (B) >)

The polyacetal copolymer (B) was prepared as follows.

300g of trioxane was charged into a closed autoclave having a jacket through which a heat medium can flow and a stirring blade, and the compound described in Table 1 as the component (b), and optionally 1, 3-Dioxolane (DO) or butanediol formal (BDF) as the component (c) were added in proportions each representing 1 part by mass. The contents were stirred, hot water at 80 ℃ was passed through the jacket, and after the internal temperature was maintained at 80 ℃, a catalyst solution (phosphotungstic acid (PWA) as a solution of methyl formate, boron trifluoride dibutyl ether complex (BF) was added₃OBu₂) Dibutyl ether solution) was adjusted to the catalyst concentration (with respect to the whole monomer) shown in table 1 to initiate polymerization. When boron trifluoride dibutyl ether complex is used, the catalyst concentration is expressed as the concentration of boron trifluoride.

The component (b) used in the examples was the following component (b-1). In the formula (b-1), Me represents a methyl group.

After 5 minutes, 300g of water containing 0.1% triethylamine was added to the autoclave to stop the reaction, and the contents were taken out, pulverized to 200 mesh or less, washed with acetone and dried to obtain a polyacetal copolymer.

For comparison, the following diglycidyl compounds (X-1 and X-2) were used in the polymerization in place of the component (b-1) of the present invention to obtain a comparative polyacetal copolymer.

X-1: butanediol diglycidyl ether

X-2: trimethylolpropane triglycidyl ether

< examples and comparative examples >

The respective components shown in table 1 were added and mixed at the ratios shown in table 1, and melt-kneaded in a vented twin-screw extruder to prepare a pellet-shaped composition.

In addition, 0.35 parts by mass of ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate ] (IRGANOX 245, manufactured by BASF Japan corporation) and 0.08 parts by mass of melamine were added to 100 parts by mass of the total amount of the component (a) and the component (B) during melt kneading of all the samples.

In comparative examples 4 and 5 using X-1 or X-2, no polymerization reaction was observed under the conditions shown in Table 1 with respect to the polyacetal copolymer (B) under other polymerization conditions, even if the polymerization conditions were the same as those in the examples, and thus no composition evaluation was conducted.

< evaluation >

The characteristic evaluation items and evaluation methods in the examples are as follows.

< tensile Strength >

The tensile strength of the test piece ISO Type1A was measured in accordance with ISO527-1, 2. The measuring chamber was kept in an atmosphere of 50% RH at 23 ℃.

< flexural Strength and flexural modulus >

Flexural modulus was determined according to ISO 178. The measuring chamber was kept in an atmosphere of 50% RH at 23 ℃.

[ Table 1]

As is clear from table 1, the compositions of the present invention are excellent in mechanical properties (tensile strength and flexural modulus).