JP2005272511A - Additive for polyester resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an additive for a polyester resin capable of improving the crystallization rate, temperature sensitivity and heat resistance of the polyester resin, and to obtain a polyester resin composition containing the additive, and to provide a manufacturing method for the polyester resin. <P>SOLUTION: The additive for the polyester resin contains silsesquioxane. The polyester resin composition contains the polyester resin and silsesquioxane. The manufacturing method for the polyester resin composition comprises the step of mixing the polyester resin and silsesquioxane at the melting point (Tm) of the polyester resin or above and the step of conducting the heat treatment in the temperature range from the glass transition temperature (Tg) of the polyester resin composition to a temperature lower than Tm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an additive for polyester resin, a polyester resin composition containing the additive, and a method for producing the same.

  General-purpose resins made from petroleum such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene are lightweight and have good processability, physical properties, and durability. Used in various fields such as building materials and food packaging. However, these resin products have a disadvantage of good durability at the stage of finishing and discarding their functions, and are inferior in degradability in nature, and thus may affect the ecosystem.

  In order to solve such problems, as a polymer having a biodegradability with a thermoplastic resin, polylactic acid, a copolymer of lactic acid and another aliphatic hydroxycarboxylic acid, an aliphatic polyhydric alcohol and an aliphatic polyvalent carboxylic acid are used. Biodegradable polyester resins such as aliphatic polyesters derived from acids and copolymers containing these units have been developed.

  When these biodegradable polyester resins are placed in soil, seawater, or the body of an animal, they start to degrade in a few weeks due to the action of enzymes produced by naturally occurring microorganisms. Disappears within a few years. Furthermore, the decomposition products become lactic acid, carbon dioxide, water, etc., which are harmless to the human body. Among the aliphatic polyesters, polylactic acid resin has been made cheap by producing a large amount of L-lactic acid from sugars obtained from corn, straw, etc. by fermentation, and the total carbon dioxide emissions are extremely low because the raw material is a natural crop. In addition, since the obtained polymer has characteristics such as high rigidity and good transparency, it is expected to be used at present, and the field of agricultural civil engineering materials such as flat yarn, nets, horticultural materials, seedling pots, with windows Used in envelopes, shopping bags, compost bags, stationery, miscellaneous goods, etc. However, since the crystallization speed of polylactic acid is significantly slower than that of polyolefin or the like, there are problems such as a decrease in heat resistance due to insufficient crystallization and an increase in cost due to a decrease in molding efficiency.

Polylactic acid is brittle, hard, and lacks flexibility, so it is limited to the field of hard molded products. When it is molded into a film, problems such as lack of flexibility or whitening when folded The current situation is that it is not used in the soft or semi-rigid field. Various methods of adding a plasticizer have been proposed as a technique applied to the soft and semi-rigid fields. For example, a technique of adding a plasticizer such as tributyl acetylcitrate or diglycerin tetraacetate is disclosed. When these plasticizers are added to polylactic acid and a film or sheet is formed by extrusion or the like, good flexibility is obtained, but because the polymer is in an amorphous state, it is flexible due to temperature changes near the glass transition point. There is a problem that the change in properties is remarkable (temperature sensitivity) and the heat resistance at high temperatures is insufficient, so that the physical properties change remarkably depending on the season, making it impossible to use in high temperature environments. In order to solve this problem, a method has been proposed in which polylactic acid is crystallized by adding a crystal nucleating agent such as a sorbitol derivative or talc (Patent Document 1, Patent Document 2) to improve heat resistance and the like. . However, there is a problem that the crystallization rate by heat treatment after molding is insufficient and the transparency of the sheet and film is lowered.
JP-A-10-158369 Japanese Patent No. 3334338

  An object of the present invention is to provide an additive for a polyester resin capable of improving the crystallization speed, temperature sensitivity and heat resistance of the polyester resin, a polyester resin composition containing the additive, and a method for producing the same. It is in.

The present invention
(1) Additive for polyester resin containing silsesquioxane,
(2) a polyester resin composition containing a polyester resin and silsesquioxane, and (3) a step of mixing the polyester resin and silsesquioxane at a melting point (Tm) or higher of the polyester resin; A method for producing a polyester resin composition, comprising a step of heat-treating the glass transition temperature (Tg) of the polyester resin composition in a temperature range less than Tm,
About.

  The polyester resin additive of the present invention (hereinafter referred to as the additive of the present invention) can improve the crystallization speed, temperature sensitivity, and heat resistance of the polyester resin, and is excellent in temperature sensitivity and heat resistance. A polyester resin composition and a method for producing the same can be provided.

[Additives for polyester resins]
The additive of the present invention contains silsesquioxane. Silsesquioxane is, for example, a compound having a structural unit of [RSiO _3/2 ] described in “Journal of Polymer Society, Vol. 47, December (1998), pages 899 to 903”. It can take the form of molecular arrangement such as structure, ladder structure, cage structure. Among these shapes, a cage structure is preferable from the viewpoint of expressing the effects of the present invention.

R in [RSiO _3/2 ] includes, for example, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a cycloalkyl group, an alkoxy group, and the like, and an alkyl group is preferable from the viewpoint of manifesting the effects of the present invention. A linear or branched alkyl group having 1 to 22 carbon atoms is more preferable, a linear or branched alkyl group having 1 to 18 carbon atoms is more preferable, and a linear or branched alkyl group having 3 to 10 carbon atoms is particularly preferable. .

In addition, R in [RSiO _3/2 ] is an atom other than a carbon atom, for example, a hydrogen atom, a boron atom, a nitrogen atom, an oxygen atom, a fluorine atom, a silicon atom, as long as the effect of the present invention is not impaired. You may contain a phosphorus atom, a sulfur atom, a chlorine atom, etc.

Specific examples of R in [RSiO _3/2 ] include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, Cyclopentyl, n-hexyl, cyclohexyl, n-octyl, n-decyl, vinyl, acetyl, phenyl, benzyl, dichloromethylsilylethyl, 2-chlorodimethylsilylethyl, dimethylsilyloxy Group, trichlorosilylethyl group, methoxy group and the like. From the viewpoint of expressing the effects of the present invention, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n -Hexyl, cyclohexyl, n-octyl and n-decyl are preferred, methyl, ethyl, n-propyl, iso-propyl, n-butyl and iso-butyl are more preferred, n- A butyl group and an iso-butyl group are particularly preferable.

The additive of the present invention is preferably a silsesquioxane having a cage structure, more preferably a cage structure of [RSiO _3/2 ] _n (6 ≦ n ≦ 12), from the viewpoint of expressing the effects of the present invention. _3/2 ] _n (n = 8) cage structure is particularly preferred. Specifically, octamethyl silsesquioxane, octaethyl silsesquioxane, octa n-propyl silsesquioxane, octa iso-propyl silsesquioxane, octa n-butyl silsesquioxane, octa iso-butyl Silsesquioxane, Octa tert-butylsilsesquioxane, Octane-pentylsilsesquioxane, Octacyclopentylsilsesquioxane, Octane-hexylsilsesquioxane, Octacyclohexylsilsesquioxane, Octane-octyl Silsesquioxane, Octane-decylsilsesquioxane, Octavinylsilsesquioxane, Octaacetylsilsesquioxane, Octaphenylsilsesquioxane, Octabenzylsilsesquioxane, Octadichloromethylsilylethylsilsesquioxane Sun, Octa 2-K From the viewpoint of expressing the effects of the present invention, there may be mentioned rodimethylsilylethylsilsesquioxane, octadimethylsilyloxysilsesquioxane, octatrichlorosilylethylsilsesquioxane, octamethoxysilsesquioxane, etc. Silsesquioxane, octaethylsilsesquioxane, octa n-propyl silsesquioxane, octa iso-propyl silsesquioxane, octa n-butyl silsesquioxane, octa iso-butyl silsesquioxane, octa tert -Butyl silsesquioxane, octa n-pentyl silsesquioxane, octacyclopentyl silsesquioxane, octa n-hexyl silsesquioxane, octacyclohexyl silsesquioxane, octa n-octyl silsesquioxane, octa n -Decylsilsesquio Sun is preferred, octamethyl silsesquioxane, octaethyl silsesquioxane, octa n-propyl silsesquioxane, octa iso-propyl silsesquioxane, octa n-butyl silsesquioxane, octa iso-butyl sil Sesquioxane is more preferable, and octa n-butyl silsesquioxane and octa iso-butyl silsesquioxane are still more preferable.

  The melting point of the additive of the present invention is preferably not less than the melting point of the polyester resin from the viewpoint of manifesting the effects of the present invention, preferably 170 to 500 ° C, more preferably 180 to 400 ° C.

The additive of the present invention is suitably used as a crystal nucleating agent for a polyester resin, and may contain an unreacted product or an existing crystal nucleating agent in silsesquioxane production.
Examples of the existing crystal nucleating agent include inorganic particles such as silica and talc, and sorbitol derivatives such as bisbenzylidene sorbitol.

  From the viewpoint of achieving the object of the present invention, the content of silsesquioxane in the additive of the present invention is preferably 80% by weight or more, more preferably 90% by weight or more, and still more preferably 95%. % By weight or more.

  The additive of the present invention is suitably used as an additive for polylactic acid resin from the viewpoint of excellent transparency retention in addition to the effects of the present invention.

[Polyester resin]
Although it does not specifically limit as polyester resin concerning this invention, The polyester obtained by condensation reaction of dicarboxylic acid or its ester-forming derivative, and diol or its ester-forming derivative, The polyester obtained from the condensation reaction of hydroxycarboxylic acid A mixture of these polyesters and a transesterification product of the mixture are suitable.

  Specific examples of the polyester resin include aromatic polyesters such as polyalkylene terephthalates including polyalkylene terephthalates such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, and polyalkylene naphthalates such as polyethylene naphthalate and polybutylene naphthalate. Resin; Aliphatic polyester resin such as polyester of adipic acid and 1,4-butanediol; Polyether ester resin in which a part of the diol component is substituted with alkylene glycol such as polyethylene glycol; Polyhydroxybutyrate, polycaprolactone, poly Butylene succinate, polybutylene succinate / adipate, polyethylene succinate, polylactic acid resin, polymalic acid, polyglycol Biodegradable aliphatic polyesters such as polydioxanone and poly (2-oxetanone); biodegradable aliphatic aromatic copolyesters such as polybutylene succinate / terephthalate, polybutylene adipate / terephthalate, and polytetramethylene adipate / terephthalate It is done. These can be used alone or in combination. Among these, a biodegradable resin is preferable from the viewpoint of exerting influence on the ecosystem and the effects of the present invention.

  The biodegradable resin used in the present invention has a biodegradability based on JIS K6953 (ISO 14855) “Aerobic and ultimate biodegradability and disintegration test under controlled aerobic compost conditions”. The polyester resin which has is preferable.

  The biodegradable resin used in the present invention is not particularly limited as long as it has a biodegradability capable of being decomposed into a low molecular weight compound with the participation of microorganisms in nature. For example, aliphatic polyesters such as polyhydroxybutyrate, polycaprolactone, polybutylene succinate, polybutylene succinate / adipate, polyethylene succinate, polylactic acid resin, polymalic acid, polyglycolic acid, polydioxanone, poly (2-oxetanone) Aliphatic aliphatic copolyesters such as polybutylene succinate / terephthalate, polybutylene adipate / terephthalate, polytetramethylene adipate / terephthalate; starch, cellulose, chitin, chitosan, gluten, gelatin, zein, soy protein, collagen, keratin, etc. And a mixture of the above natural polymer and the above aliphatic polyester or aliphatic aromatic copolyester.

  Of these, aliphatic polyesters are preferable from the viewpoint of processability, economy, and availability in large quantities, and polylactic acid resins are more preferable from the viewpoint of physical properties. Here, the polylactic acid resin is polylactic acid or a copolymer of lactic acid and hydroxycarboxylic acid. Examples of the hydroxycarboxylic acid include glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid and the like, and glycolic acid and hydroxycaproic acid are preferable. A preferred molecular structure of polylactic acid is composed of 20 to 100 mol% of either L-lactic acid or D-lactic acid and 0 to 20 mol% of each enantiomer. The copolymer of lactic acid and hydroxycarboxylic acid is composed of 85 to 100 mol% of either L-lactic acid or D-lactic acid and 0 to 15 mol% of hydroxycarboxylic acid units. These polylactic acid resins can be obtained by dehydrating polycondensation using L-lactic acid, D-lactic acid and hydroxycarboxylic acid as raw materials by selecting those having the required structure. Preferably, it can be obtained by ring-opening polymerization by selecting a desired structure from lactide, which is a cyclic dimer of lactic acid, glycolide, which is a cyclic dimer of glycolic acid, and caprolactone. Lactide includes L-lactide which is a cyclic dimer of L-lactic acid, D-lactide which is a cyclic dimer of D-lactic acid, meso-lactide obtained by cyclic dimerization of D-lactic acid and L-lactic acid, and D-lactide. There is DL-lactide, which is a racemic mixture of lactide and L-lactide. Any lactide can be used in the present invention. However, the main raw material is preferably D-lactide or L-lactide.

  Examples of commercially available biodegradable resins include DuPont, trade name Biomax; BASF, trade name Ecoflex; Eastman Chemicals, trade name EsterBio; Showa Polymer Co., Ltd., trade name Bionore; Nippon Synthetic Chemical Industry Co., Ltd., trade name: Matterby; Mitsui Chemicals, Inc., trade name: Lacia; Nippon Shokubai Co., Ltd., trade name: Lunare; Chisso Corporation, trade name: Novon; Cargill Dow Polymers The product name Nature Works etc. is mentioned.

  Among these, a polylactic acid resin (for example, Mitsui Chemical Co., Ltd., trade name Lacia H-100, H-280, H-400, H-440; Cargill Dow Polymers, trade name Nature Works) is preferable. ), Aliphatic polyesters such as polybutylene succinate (product name Bionore, manufactured by Showa Polymer Co., Ltd.), aliphatic aromatic copolyesters such as poly (butylene succinate / terephthalate) (trade name Bio, manufactured by DuPont) Max).

  From the viewpoint of heat resistance, a crystalline biodegradable resin having a high L-lactic acid purity is preferred, and orientation crystallization is preferred by stretching. Examples of the crystalline biodegradable resin include Laissia H-100, H-400, and H-440 manufactured by Mitsui Chemicals.

[Plasticizer]
The polyester resin composition of the present invention can further contain a plasticizer from the viewpoint of imparting flexibility. The plasticizer used in the present invention is not particularly limited, and examples thereof include those shown in the following (1) to (9) in addition to the plasticizer used in general polyester resins.
(1) Esters of the following (a) component and (b) component (a) General formula (III)

(In the formula, X ¹ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 22 carbon atoms, an alkenyl group, an alkoxy group, or a halogen atom, and d and e are each an integer of 1 or more, and d + e = 5. f represents an integer of 0 to 3. The d X ¹ may be the same or different.
Hydroxy aromatic carboxylic acid represented by the formula, hydroxy condensed polycyclic aromatic carboxylic acid having at least one hydroxyl group and carboxyl group in the molecule, hydroxy alicyclic carboxylic acid, anhydride of these carboxylic acids or carbon number At least one selected from 1 to 3 lower alkyl esters.
(B) Hydroxy compounds selected from aliphatic alcohols, alicyclic alcohols, aromatic alcohols, phenols and alkylphenols, or alkylene oxide adducts of these hydroxy compounds (alkylene group having 2 to 4 carbon atoms, alkylene oxide average addition mole) At least one selected from a number greater than 0 and 30 or less.
(2) Esters of the following (c) component and (d) component (c) General formula (IV)

(In the formula, X ² represents a hydrogen atom, a methyl group or a halogen atom, g and h are each an integer of 1 or more, and g + h = 6. The g X ² may be the same or different.)
Or a condensed polycyclic aromatic carboxylic acid having one or more carboxyl groups in one molecule, an alicyclic carboxylic acid, an anhydride of these carboxylic acids, or a lower one having 1 to 3 carbon atoms. At least one selected from alkyl esters.
(D) Alkylene oxide adducts of monohydroxy compounds selected from aliphatic monoalcohols, alicyclic monoalcohols, aromatic monoalcohols, phenols and alkylphenols (alkylene groups having 2 to 4 carbon atoms, average number of moles of alkylene oxide added) 1 to 30).
(3) N-alkylated products of aromatic sulfonamides (alkyl groups having 1 to 22 carbon atoms)
(4) Ester of the following (e) component and (f) component (e) General formula (V)

(Wherein X ³ represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, an alkenyl group or an alkoxy group, or a halogen atom, i represents an integer of 1 to 5, and i pieces of X ³ may be the same or different. May be good.)
An aromatic monocarboxylic acid represented by the formula, a linear or branched aliphatic monocarboxylic acid having 1 to 22 carbon atoms, a condensed polycyclic aromatic monocarboxylic acid, an alicyclic monocarboxylic acid, or lower of these monocarboxylic acids At least one selected from alkyl esters (alkyl groups having 1 to 3 carbon atoms).
(F) General formula (VI)

(In formula, Y and Z show a C1-C8 alkyl group or an alkenyl group, and may be same or different.)
Selected from the group consisting of aliphatic dihydric alcohols, polyhydric alcohols having 3 to 30 carbon atoms having three or more hydroxyl groups in one molecule, and alicyclic diols having two hydroxyl groups or methylol groups in one molecule. At least one selected from alkylene oxide adducts of a hydroxy compound (an alkylene group having 2 to 4 carbon atoms and an alkylene oxide average addition mole number per hydroxyl group of greater than 0 and 10 or less).
(5) Aliphatic dicarboxylic acid polyoxyalkylene alkyl ether ester, polyalkylene glycol fatty acid ester, or ester of aliphatic polyhydric alcohol and benzoic acid (6) Ester of the following (g) component and (h) component (g General formula (VII)

(Wherein j represents an integer of 2 to 6)
A polycarbonate diol comprising a repeating structural unit represented by the following (hereinafter referred to as structural unit (VII)) and having both hydroxyl groups.
(H) General formula (VIII)

(In the formula, X ⁴ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 22 carbon atoms, an alkenyl group or an alkoxy group, or a halogen atom, k represents an integer of 1 to 5, and k X ⁴ may be the same or different.)
An aromatic monocarboxylic acid, a condensed polycyclic aromatic monocarboxylic acid, an alicyclic monocarboxylic acid, a hydroxy condensed polycyclic aromatic monocarboxylic acid having one or more hydroxyl groups in the molecule, hydroxy At least one selected from alicyclic monocarboxylic acids, anhydrides of these carboxylic acids, or lower alkyl esters having 1 to 3 carbon atoms.
(7) Ester of the following component (i) and component (j) (i) At least one selected from carboxylic acids having at least one cyano group, anhydrides of these carboxylic acids, or lower alkyl esters having 1 to 3 carbon atoms seed.
(J) Hydroxy compounds selected from aliphatic alcohols, alicyclic alcohols, aromatic alcohols, phenols and alkylphenols, or alkylene oxide adducts of these hydroxy compounds (2-4 carbon atoms of alkylene groups, average addition of alkylene oxides) At least one selected from the group consisting of more than 0 and 30 or less.
(8) Ester of the following (k) component and (l) component (k) At least one selected from alkylene oxide adducts of a polyhydric alcohol having 3 or more carbon atoms and having 3 or more hydroxyl groups in one molecule.
(L) At least one selected from linear or branched fatty acids having 2 to 12 carbon atoms or lower alkyl esters having 1 to 3 carbon atoms.
(9) A cyclic acetal obtained by subjecting the following component (m) and component (n) to an acetalization reaction or a transacetalization reaction.
(M) At least one of trihydric or higher polyhydric alcohols.
(N) At least one selected from the group consisting of a carbonyl compound represented by the general formula (IX) and an acetal obtained from the carbonyl compound and a lower alcohol having 1 to 6 carbon atoms.

Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom or a linear, branched or cyclic alkyl group having ¹ to 21 carbon atoms, and R ¹ and R ² together represent 2 to 2 carbon atoms. 24 alkylene groups may be formed.)

As the ester of (1), the component (a) is p-hydroxybenzoic acid or salicylic acid, and the component (b) is represented by the general formula (X).
R ³ O (AO) _n1 H (X)
(Wherein R ³ is a hydrogen atom, a linear or branched alkyl group or alkenyl group having 1 to 22 carbon atoms, a phenyl group, a benzyl group, or an alkylphenyl group or alkylbenzyl group having an alkyl group having 1 to 18 carbon atoms. A is an alkylene group having 2 to 4 carbon atoms, n1 is a number from 0 to 30 indicating the average number of added moles of alkylene oxide, and n1 A may be the same or different.
Or an alkylene oxide adduct of a polyhydric alcohol having 3 to 30 carbon atoms having 3 or more hydroxyl groups in one molecule (an alkylene oxide having 2 to 4 carbon atoms in an alkylene group and an average of alkylene oxide per hydroxyl group) Esters obtained from combinations where the number of moles added is greater than 0 and less than 10) are preferred.

As the ester of the above (2), the component (c) is benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid or anhydrides thereof or those having 1 to 3 carbon atoms. A lower alkyl ester, wherein the component (d) is represented by the general formula (XI)
R ⁴ O (AO) _n2 H (XI)
(In the formula, R ⁴ is a linear or branched alkyl group or alkenyl group having 1 to 22 carbon atoms, a phenyl group, a benzyl group, or an alkylphenyl group having an alkyl group having 1 to 18 carbon atoms, and A is a carbon number. (2 to 4 alkylene groups, n2 is a number of 1 to 30 indicating the average number of added moles of alkylene oxide, and n2 A may be the same or different.)
The ester obtained from the combination which is a compound represented by these is preferable.

  The N-alkylated product of the aromatic sulfonamide (3) above has the general formula (XII)

(In the formula, R ⁵ represents a linear or branched alkyl group having 1 to 22 carbon atoms.)
N-alkylbenzenesulfonamide represented by the formula is preferred.

  As the ester of (4) above, (e) component benzoic acid optionally having an alkyl group having 1 to 6 carbon atoms or a halogen atom as a substituent or a lower alkyl ester thereof (alkyl group having 1 to 3), and (f) component is neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, glycerin, sorbitol, sorbitan, trimethylolpropane, pentaerythritol, cyclohexanediol, cyclohexanedimethanol ethylene Preference is given to esters obtained from combinations which are oxide adducts (average addition moles of ethylene oxide per hydroxyl group greater than 0 and not more than 10).

  As the ester of (5), dipropylene glycol benzoic acid diester, ethylene glycol benzoic acid diester, neopentyl glycol benzoic acid diester, polyoxyethylene methyl ether adipic acid diester and the like are preferable.

  As the ester of (6), the component (g) includes a polycarbonate diol having an average molecular weight of 400 to 3000, particularly two or more structural units (VII) having different integers j. A random or block polycarbonate diol having a molar fraction of 85% or less, and obtained from a combination in which component (h) is benzoic acid, salicylic acid, p-hydroxybenzoic acid, or a lower alkyl ester having 1 to 3 carbon atoms thereof. The esters obtained are preferred.

  As the ester of the above (7), the component (i) is represented by the general formula (XIII)

(In the formula, X ⁵ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 22 carbon atoms, an alkenyl group or an alkoxy group, or a halogen atom, and p, q and r are each an integer of 1 or more. P + q + r = 6.q X ⁵ may be the same or different.)
Cyanoaromatic carboxylic acid represented by the general formula (XIV)
_{NC- (CH 2) n3 -COOH (} XIV)
(In the formula, n3 represents an integer of 1 to 8.)
Or a lower alkyl ester having 1 to 3 carbon atoms represented by formula (X), wherein the component (j) is a general formula (XV)
R ⁶ O (AO) _n4 H (XV)
(In the formula, R ⁶ is a hydrogen atom, a linear or branched alkyl group having 1 to 22 carbon atoms or an alkenyl group, a phenyl group, a benzyl group, or an alkylphenyl group or alkylbenzyl group having an alkyl group having 1 to 18 carbon atoms. A is an alkylene group having 2 to 4 carbon atoms, n4 is a number from 0 to 30 indicating the average number of added moles of alkylene oxide, and n4 A may be the same or different.
The ester obtained from the combination which is a compound represented by these is preferable.

  As the ester of (8), the (k) component is an alkylene oxide adduct of a polyhydric alcohol having 3 to 30 carbon atoms having 3 to 12 hydroxyl groups in one molecule (the alkylene oxide has 2 to 4 carbon atoms). The average added mole number of alkylene oxide is 0.2 to 10 per hydroxyl group of the polyhydric alcohol, and (l) the component is a linear or branched fatty acid having 2 to 12 carbon atoms, particularly acetic acid. The resulting ester is preferred.

As the cyclic acetal of (9) above, the component (m) is a 4- to 10-valent polyhydric alcohol such as diglycerin, polyglycerin, dipentaerythritol, ditrimethylolethane, ditrimethylolpropane, sugar alcohol, and the like (n A cyclic acetal obtained from a combination in which the component is a carbonyl compound in which R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms and R ² is an alkyl group having 1 to 12 carbon atoms in the general formula (IX) preferable.

  Among such plasticizers used in the present invention, from the viewpoint of excellent flexibility, transparency and bleed resistance of the polyester resin, hydroxybenzoic acid esters such as 2-ethylhexyl hydroxybenzoate, ethylene oxide adducts of glycerin Polyhydric alcohol esters such as acetate ester, phthalate esters such as di-2-ethylhexyl phthalate, adipate esters such as dioctyl adipate, maleate esters such as di-n-butyl maleate, tributyl acetylcitrate, etc. Alkyl citrate, alkyl phosphate such as tricresyl phosphate, tricarboxylic acid ester such as trioctyl trimellitic acid, alkyl ether of polyvalent carboxylic acid such as ester of 1,3,6-hexatricarboxylic acid and butyl diglycol Esters, general formula (XVI Or (XVII)

(Wherein, R ⁷ and R ⁸ in R ⁷ is a hydrogen atom, or R ⁸ is a straight-chain or branched-chain alkyl group branched alkyl group or a C 4-21 3 carbon atoms, or R ⁷ Is a linear or branched alkyl group having 1 to 21 carbon atoms, and R ⁸ is a linear or branched alkyl group having 2 to 21 carbon atoms.)
And a cyclic acetal such as a cyclic acetal obtained from diglycerin and polyglycerin is preferable, and the ester of the above (8) is more preferable.

[Polyester resin composition]
The polyester resin composition of the present invention contains the additive of the present invention and a polyester resin. The content of the additive of the present invention in the polyester resin composition is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 100 parts by weight of the polyester resin from the viewpoint of expressing the effects of the present invention. ˜2 parts by weight, particularly preferably 0.5 to 1.5 parts by weight.

  From the viewpoint of excellent transparency retention, the additive of the present invention is suitably used for a polylactic acid resin having transparency, and the polyester resin composition of the present invention can be obtained. The haze value at a thickness of 500 μm of the polyester resin composition is preferably 30% or less, more preferably 25% or less. In addition, the haze value of the polyester resin composition of this invention is a value measured by the measuring method described in the Example here.

  The polyester resin composition of the present invention can further contain a plasticizer from the viewpoint of imparting flexibility. The content of the plasticizer in the polyester resin composition is preferably 1 to 70 parts by weight, more preferably 3 to 50 parts by weight, particularly preferably 100 parts by weight of the polyester resin from the viewpoint of flexibility and bleed resistance. Is 5 to 45 parts by weight.

When the polyester resin composition of the present invention further contains a plasticizer, in addition to the effects of the present invention, a polyester resin composition having excellent flexibility can be obtained. The storage elastic modulus (E ′) of the polyester resin composition is preferably a storage elastic modulus (E ′) at a temperature of 25 ° C. and a frequency of 50 Hz of 1 × 10 ⁸ to 2 × 10 ⁹ Pa, and a temperature of 60 The storage elastic modulus (E ′) at 1 ° C. and a frequency of 50 Hz is 1 × 10 ⁷ to 1 × 10 ⁹ Pa. More preferably, the storage elastic modulus (E ′) at a temperature of 25 ° C. and a frequency of 50 Hz is 1. × a 10 ⁸ ~1 × 10 ⁹ Pa, and a temperature of 60 ° C., a storage modulus at frequency of 50 Hz (E ') is ^{1 × 10 7 ~1 × 10 9} Pa. In addition, the storage elastic modulus (E ') of the polyester resin composition of this invention is a value measured by the measuring method described in the Example here.

  The degree of crystallinity of the polyester resin composition of the present invention varies depending on the type of polyester resin, the presence or absence of a plasticizer, and so on, but cannot be determined unconditionally. 50%, more preferably 10 to 40%. In addition, the crystallinity degree of the polyester resin composition of this invention is a value measured by the measuring method described in the Example here.

  The polyester resin composition of the present invention can contain other components such as a lubricant in addition to the additive and plasticizer of the present invention. Examples of the lubricant include hydrocarbon waxes such as polyethylene wax, fatty acids such as stearic acid, fatty acid esters such as glycerol ester, metal soaps such as calcium stearate, ester waxes such as montanic acid wax, and alkylbenzene sulfone. Anionic surfactants having an aromatic ring such as acid salts, anionic surfactants having an alkylene oxide addition moiety such as polyoxyethylene alkyl ether sulfate, and the like. The content of these lubricants is preferably 0.05 to 3 parts by weight and more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the polyester resin.

  The polyester resin composition of the present invention includes an antistatic agent, an antifogging agent, a light stabilizer, an ultraviolet absorber, a pigment, an inorganic filler, an antifungal agent, an antibacterial agent, a foaming agent, a difficult component, as components other than the above. A flame retardant, a plasticizer other than the plasticizer of the present invention, and the like can be contained within a range that does not hinder the achievement of the object of the present invention.

  Since the polyester resin composition of the present invention has good processability and can be processed at a low temperature such as 130 to 200 ° C., there is also an advantage that the plasticizer is hardly decomposed. It can be used for various purposes.

  As a method for producing the polyester resin composition of the present invention, for example, the polyester resin and the additive of the present invention are mixed at a temperature equal to or higher than the melting point (Tm) of the polyester resin and mixed, and then cooled. And a step of heat-treating the polyester resin composition obtained in the temperature range from the glass transition temperature (Tg) to less than Tm. Further, as a method for producing the polyester resin composition of the present invention in the case of further containing a plasticizer, for example, the polyester resin, the additive of the present invention, and the plasticizer may be used at a melting point (Tm) or higher of the polyester resin. The glass transition of the polyester resin composition obtained in the amorphous state (that is, the condition that the crystallinity measured by the wide angle X-ray diffraction method is 1% or less) after cooling through the mixing step and the mixing step And a step of performing a heat treatment in a temperature range from temperature (Tg) to less than Tm. In addition, the crystallinity degree of the polyester resin composition of this invention is a value measured by the measuring method described in the Example here.

  In the method for producing the polyester resin composition of the present invention, the mixing step can be carried out by an ordinary method. For example, while the polyester resin is melted using an extruder or the like, the additive of the present invention is used. If necessary, a method of mixing a plasticizer may be used. From the viewpoint of the dispersibility of the additive and plasticizer of the present invention, the temperature of the mixing step is not less than the melting point (Tm) of the polyester resin, preferably Tm to Tm + 100 ° C., more preferably Tm to Tm + 50 ° C. is there.

  Specific examples of the heat-treating step in the method for producing the composition of the present invention can be performed by an ordinary method, and examples thereof include a method of heat-treating a polyester resin composition extruded by an extruder or the like. The temperature of the heat treatment step is less than Tm from the glass transition temperature (Tg) of the polyester resin composition, preferably Tg to Tg + 100 ° C., more preferably Tg to Tg + 50 ° C., from the viewpoint of improving the crystallization speed. .

  In addition, melting | fusing point (Tm) of a polyester resin is a value calculated | required from the crystal melting endothermic peak temperature by the temperature rising method of the differential scanning calorimetry (DSC) based on JIS-K7121.

  The glass transition temperature (Tg) of the polyester resin composition is a value obtained from the peak temperature of the loss elastic modulus (E ″) in the dynamic viscoelasticity measurement, and the value is the dynamic value described in the examples. It is a value measured by a method for measuring viscoelasticity.

Example 1 and Comparative Examples 1-3
As a polyester resin, 100 parts by weight of a polylactic acid resin (manufactured by Mitsui Chemicals, LACEA H-280), a composition comprising the additive and plasticizer of the present invention in the types and amounts shown in Table 1, 4 inches at 130 ° C. The mixture was kneaded for 15 minutes with a roll (manufactured by Nishimura Machinery Co., Ltd.), and a test piece having a thickness of 500 μm was prepared with a press molding machine at 160 ° C.
The obtained test piece was left to stand in an oven controlled at 60 ° C. for 12 hours and 36 hours for heat treatment.

  The obtained test pieces were evaluated for crystallization speed, temperature sensitivity, heat resistance, flexibility, transparency, and bleed resistance by the following methods. These results are shown in Table 1.

<Evaluation method of crystallization rate>
Using a wide-angle X-ray diffractometer (RINT2500VPC, light source CuKα, tube voltage 40kV, tube current 120mA, manufactured by Rigaku Corporation) using a non-heat-treated test piece and a heat-treated test piece at 60 ° C for 12 hours and 36 hours. The crystal peak area was analyzed to determine the crystallinity, and the crystallization rate was evaluated.

<Method for evaluating temperature sensitivity, heat resistance and flexibility>
The test piece obtained above is stored in a dynamic viscoelasticity measuring device (DVA-200 manufactured by IT Measurement Control) in a temperature range of −20 ° C. to 80 ° C. at a frequency of 50 Hz and a heating rate of 2 ° C./min. The temperature change of the elastic modulus (E ′) was examined. As an example, FIG. 1 shows the results of measuring the temperature change of the storage elastic modulus (E ′) for the test sheets obtained in Example 1, Comparative Example 1 and Comparative Example 3. Table 1 shows the measured values of the storage elastic modulus (E ′) at 0 ° C., 25 ° C. and 60 ° C.

<Transparency evaluation method>
The haze value of the test piece was measured using an integrating sphere light transmittance measuring device (haze meter) defined in JIS-K7105. Smaller numbers indicate better transparency.

<Bleed resistance evaluation method>
The test piece before heat treatment (length 100 mm × width 100 mm × thickness 500 μm) was left in a constant temperature room at 40 ° C. for one week, and the presence or absence of a plasticizer bleed on the surface was observed with the naked eye. The test pieces after heat treatment at 60 ° C. for 12 hours and 36 hours were also evaluated in the same manner. The one without bleed indicates that the surface condition is good.

Example 2 and Comparative Examples 4-6
As a polyester resin, a composition comprising 100 parts by weight of a polylactic acid resin (manufactured by Mitsui Chemicals, LACEA H-280), the type and amount of the additive of the present invention shown in Table 2, and a plasticizer is used. The mixture was kneaded for 10 minutes with a mill (manufactured by Toyo Seiki Seisakusho), and a test piece having a thickness of 500 μm was prepared with a press molding machine at 180 ° C.
The obtained test piece was left to stand in an oven controlled at 60 ° C. for 3 hours for heat treatment.

  The obtained test pieces were evaluated for crystallization speed, temperature sensitivity, heat resistance, flexibility, transparency, and bleed resistance by the above methods. These results are shown in Table 2.

It is a graph which shows the temperature change of a storage elastic modulus (E ') about the test sheet | seat obtained in Example 1, the comparative example 1, and the comparative example 3. FIG.

Claims (9)

  Additive for polyester resin containing silsesquioxane.   The additive for a polyester resin according to claim 1, which is used as a crystal nucleating agent.   The additive for a polyester resin according to claim 1 or 2, wherein the polyester resin is a polylactic acid resin.   A polyester resin composition comprising a polyester resin and silsesquioxane.   Furthermore, the polyester resin composition of Claim 4 containing a plasticizer.   The polyester resin composition according to claim 4 or 5, wherein the polyester resin composition has a haze value of 30% or less at a thickness of 500 µm. The storage elastic modulus (E ′) at a temperature of 25 ° C. and a frequency of 50 Hz of the polyester resin composition is 1 × 10 ⁸ to 2 × 10 ⁹ Pa, and the storage elastic modulus (E ′) at a temperature of 60 ° C. and a frequency of 50 Hz. ) Is 1 × 10 ⁷ to 1 × 10 ⁹ Pa. The polyester resin composition according to claim 4.   The polyester resin composition according to any one of claims 4 to 7, wherein the polyester resin is a polylactic acid resin. A step of mixing a polyester resin and silsesquioxane at a melting point (Tm) or higher of the polyester resin, and a step of heat-treating the polyester resin composition at a temperature range lower than Tm from the glass transition temperature (Tg). A method for producing a polyester resin composition.

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