JP3907376B2 - Optical element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a copolymer of lactic acid and other than lactic acid (co) polymerizable polyfunctional compounds, an optical optical element obtained from the composition and the composition you comprising a cholesteric liquid crystal compound .
[0002]
[Prior art]
As an optical rotator for rotating the direction of linearly polarized light and elliptically polarized light such as a half-wave plate, an optical rotatory crystal plate and a phase difference plate, an optical rotator such as quartz or a birefringent crystal such as calcite It has been known. However, it is said that it is difficult to form a large area due to low productivity because it requires advanced technology and a lot of labor and time for crystal adjustment and polishing processing for accuracy improvement, and it is inflexible. There was a problem.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to solve the prior art problems as described above, to provide an optical optical element obtained from the good composition and the composition of the moldability.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a composition and a harmful composition containing a copolymer of lactic acid and a polyfunctional compound capable of (co) polymerization other than lactic acid, and a cholesteric liquid crystal compound. by using a light optical element obtained from, found finding that can solve the above problems, the present invention has been completed based on this finding. That is, the present invention is specified by the matters described in [1] to [22] below.
[0005]
[1] A copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid, and a cholesteric liquid crystal compound "copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid" The composition comprises 0.001 to 30% by weight based on the weight of
[0006]
[2] The composition according to [1], wherein the copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid includes a copolymer of lactic acid and a hydroxycarboxylic acid other than lactic acid . .
[0007]
[3] The copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid includes a copolymer of lactic acid and a polyhydric alcohol / polycarboxylic acid polymer [1] The described composition.
[0008]
[4] “(Co) polymerizable polyfunctional compound other than lactic acid” is a hydroxycarboxylic acid other than lactic acid, cyclic ester, polyvalent carboxylic acid, polyhydric carboxylic acid anhydride, polyhydric alcohol, polysaccharide, And the composition as described in any one of [1]-[3] which is at least 1 type selected from the group which consists of aminocarboxylic acid .
[0009]
[5] Hydroxycarboxylic acids other than lactic acid are glycolic acid, dimethylglycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, 2-hydroxyvaleric acid 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 2-hydroxycaproic acid, 3-hydroxycaproic acid, 4-hydroxycaproic acid, 5-hydroxycaproic acid, 6-hydroxycaproic acid, 6 -The composition as described in [4] which is at least 1 type selected from the group which consists of hydroxymethyl caproic acid and mandelic acid .
[0010]
[6] The composition described in [4], wherein the cyclic ester is at least one selected from the group consisting of glycolide, β-methyl-δ-valerolactone, γ-valerolactone, and ε-caprolactone .
[0011]
[7] The polyvalent carboxylic acid is selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and terephthalic acid The composition described in [4], which is at least one of the above .
[0012]
[8] The polyhydric alcohol is ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1 , 5-pentanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, tetramethylene glycol, and 1,4-hexanedi The composition according to [4], which is at least one selected from the group consisting of methanol .
[0013]
[9] The composition according to [4], wherein the polysaccharide is at least one selected from the group consisting of cellulose and chemically modified cellulose .
[0014]
[10] The composition according to [4], wherein the aminocarboxylic acid is an α-amino acid.
[0015]
[11] The isomer content in the lactic acid-derived repeating unit in the “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” is 0 to 10 mol%. ] The composition as described in any one of [10] .
[0016]
[12] The composition described in any one of [ 1 ] to [ 11 ] , wherein the cholesteric liquid crystal compound is a halogen compound of cholesterol .
[0017]
[13] The composition described in any one of [ 1 ] to [ 12 ] , which has optical activity .
[0018]
[14] The compositions described [13] with optical properties in at least two axial directions.
[0019]
[15] An optical element obtained from the composition according to [ 1 ] to [ 14 ] .
[0020]
[16] An optical element, wherein the optical element described in [ 15 ] is a light modulation element.
[0021]
[17] driving frequency is 1MHz～100GHz, optical element as described in [16].
[0022]
[18] driving voltage is 0.01kV / m~1MV / m, the optical element described in [16] or [17].
[0023]
[19] [15] - an optical element that have a shape of a fiber as described in any one of [18].
[0024]
[20] [15] The optical element that have a shape of the film according to any one of - [18].
[0025]
[21] [15] - an optical element having the shape of a sheet according to either one of [18].
[0026]
[22] [15] - [18] The length and thickness ratio is 3 to 1 or more moldings der Ru optical element according to any one of.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0031]
[Copolymer of lactic acid and (co) polymerizable polyfunctional compound other than lactic acid]
In the present invention, the arrangement pattern of “a copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” is a random copolymer, an alternating copolymer, a block copolymer, or a graft copolymer. Any of them may be combined. Furthermore, these may be at least partially crosslinked with a polyvalent isocyanate such as xylylene diisocyanate or 2,4-tolylene diisocyanate, or a crosslinking agent such as a polysaccharide such as cellulose, acetyl cellulose or ethyl cellulose, and at least A part thereof may have any structure such as a linear shape, an annular shape, a branched shape, a star shape, or a three-dimensional network structure, and is not limited at all.
[0032]
[Lactic acid]
Examples of the lactic acid used as a raw material include L-lactic acid, D-lactic acid, DL-lactic acid, and mixtures thereof. When lactide, which is a cyclic dimer of lactic acid, is used as a raw material for a resin, L-lactide is used. , D-lactide, meso-lactide, or a mixture thereof.
A copolymer of lactic acid having a desired optical purity and a (co) polymerizable polyfunctional compound other than lactic acid can be polymerized by variously combining these optical isomer raw materials and depending on the reaction conditions. However, the isomer content is preferably 0 to 10%, more preferably 0 to 5%, and still more preferably 0 to 2%. For example, when lactic acid is L-lactic acid, the content of D-lactic acid is preferably 0 to 10%, more preferably 0 to 5%, and still more preferably 0 to 2%.
[0033]
[Copolymerizable polyfunctional compound]
Examples of the copolymerizable polyfunctional compound include glycolic acid, dimethyl glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, 2-hydroxy Valeric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 2-hydroxycaproic acid, 3-hydroxycaproic acid, 4-hydroxycaproic acid, 5-hydroxycaproic acid, 6-hydroxycaproic acid Hydroxycarboxylic acids such as 6-hydroxymethylcaproic acid and mandelic acid; cyclic esters such as glycolide, β-methyl-δ-valerolactone, γ-valerolactone and ε-caprolactone; oxalic acid, malonic acid, succinic acid, glutar Acid, adipic acid, pimelic acid, azelaic acid, sebacic acid Polycarboxylic acids such as undecanedioic acid, dodecanedioic acid and terephthalic acid, and their anhydrides; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3- Butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neo Examples thereof include polyhydric alcohols such as pentyl glycol, tetramethylene glycol, and 1,4-hexanedimethanol; polysaccharides such as cellulose; aminocarboxylic acids such as α-amino acids;
These copolymerizable polyfunctional compounds may be one kind or a mixture of two or more kinds, and if they have asymmetric carbon, they may be L-form, D-form, and a mixture of any ratio thereof. Good.
[0034]
[Method for producing a copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid]
The method for producing “a copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention is not particularly limited. For example, JP-A-59-096123 and JP-A-7- US Pat. No. 4,057,357, Polymer Bulletin, 14, 491-495 (1985), Makromol. Chem. 187, 1611-1628 (1986), etc., and the like, and the like by a ring-opening polymerization method using lactide, which is a cyclic dimer of lactic acid.
[0035]
[Weight average molecular weight of a copolymer of lactic acid and (co) polymerizable polyfunctional compound other than lactic acid]
The weight average molecular weight (Mw) of the “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention is not particularly limited, but is 10,000 to 10,000,000. Is preferable, 30,000 to 3,000,000 is more preferable, and 50,000 to 1,000,000 is more preferable. The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of “a copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention are as follows: By appropriately selecting reaction conditions such as the kind of solvent, the kind of solvent, the kind and amount of the catalyst, the reaction temperature, the reaction time, and the degree of dehydration of the reaction system, it can be controlled to a desired one.
The “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention can be widely used as an optical element because of its high transparency.
[0036]
[Optical rotation of copolymer of lactic acid and (co) polymerizable polyfunctional compound other than lactic acid]
The “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention has an asymmetric carbon in the main chain, and thus exhibits high optical rotation by appropriate structural control. It can be shown.
When used as an optical rotator, the optical rotation is not particularly limited, but it is usually preferably 10 to 10000 ° / 1 mm.
[0037]
[Additive]
In the “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention, an additive can be added for the purpose of improving optical rotation and other physical properties. .
Specific examples of such additives include, for example, glycolic acid, dimethyl glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, 2-hydroxy Valeric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 2-hydroxycaproic acid, 3-hydroxycaproic acid, 4-hydroxycaproic acid, 5-hydroxycaproic acid, 6-hydroxycaproic acid , Hydroxycarboxylic acids such as 6-hydroxymethylcaproic acid and mandelic acid;
Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, polycarboxylic acid such as terephthalic acid, and their anhydrides and their monoamides And their diamides;
Ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2, Polyhydric alcohols such as 3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, tetramethylene glycol, 1,4-hexanedimethanol, glycerol;
Polyvalent amines such as ethylenediamine, propanediamine, butanediamine, pentanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine;
Glyceraldehyde, erythrose, threose, ribose, arabinose, xylose, lyxose, allose, altrose, glucose, mannose, gulose, idose, galactose, talose, fructose, 2-deoxyribose;
Alditols such as mannitol and glucitol;
Inositol, myo-inositol; monosaccharides such as glucosamine, disaccharides such as sucrose, lactose, maltose, cellobiose, trehalose, trisaccharides such as raffinose, starch, amylose, amylopectin, cellulose, lignin, chitin, chitosan, linaken, pectin, heparin Polysaccharides and derivatives thereof such as alanine, valine, leucine, isoleucine, methionine, tryptophan, phenylalanine, proline, glycine, serine, threonine, cysteine, tyrosine, asparagine, glutamine, lysine, histidine, arginine, aspartic acid, glutamic acid, L -Ornithine, β-alanine, γ-aminobutyric acid, ω-ester of acidic amino acid, N-substituted basic amino acid, aspartic acid-L-phenylalanine dimer ( Suparutemu) amino acids and amino acid derivatives such as, L- amino acids such as cysteic acid or the like, amino acids such as α- amino acid, polylysine, polyglutamic acid, polyaspartic acid, polypeptides and derivatives thereof such as proteins;
Cholesteryl bromide, cholesteryl-n-hexyl ether, cholesteryl-n-heptanoate, cholesteryl-n-heptyl carbonate, cholesteryl-n-heptyl mercaptocarbonate, cholesteryl benzoate, cholesteryl-ω-phenylheptanoate, cholesteryl elcate, 4-n-dodecyl Cholesterol halides such as oxy-1-naphthyridine-cholesteryl-p-aminobenzoate, fatty acid esters, carbonate esters, N- (4-ethoxybenzylidene) -4- (2-methylbutyl) aniline, 4-ethoxy-4′- (2-Methylbutyl) azobenzene, 4-ethoxy-4 ′-(2-methylbutyl) azoxybenzene, 4- (2-methylbutyl) benzoic acid-4′-n-hexyloxyphenyl ester 4-n-heptoxy-4 ′-(2-methylbutyloxycarbonyl) biphenyl, 4- [4- (2-methylbutyl) benzoyloxy] benzoic acid-4′-n-pentylphenyl ester, 4- [4- ( 2-Methylbutyl) benzoyloxy] benzoic acid-4′-cyanophenyl ester, 4- [4- (2-methylbutyl) benzoyloxy] benzoic acid-4′-nitrophenyl ester, 4- [4- (3-methylpentyl) ) Benzoyloxy] benzoic acid-4′-methylphenyl ester, 4- (2-methylbutyl) -4′-cyanobiphenyl, 4- (3-methylpentyl) -4′-cyanobiphenyl, 4- (3-methylpentyl) ) -4′-cyanobiphenyl, 4- [4- (2-methylbutyl) phenyl] benzoic acid-4′-butylphenyl ester, 4- [4 (2-Methylbutyl) phenyl] benzoic acid-4′-cyanophenyl ester, trans-4- (2-methylbutyl) cyanohexylcarboxylic acid-4′-cyanobiphenyl ester, 4-n-hexyloxybenzoic acid-4′- Examples thereof include liquid crystal compounds such as (2-methylbutoxycarbonyl) phenyl ester and 4- (4-methylbutyl) -4 ″ -cyano-p-terphenyl, and cholesteric liquid crystal compounds.
[0038]
[Composition ratio of additives]
The composition ratio of the additive added to the “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention is not particularly limited as long as it can substantially function. Is usually 0.001 to 30% by weight, preferably 0.01 to 20% by weight, based on the weight of “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid”. More preferably, it is 0.1 to 10% by weight.
By adding these additives, for example, optical rotation can be imparted in at least two axial directions, and in this case, the additive is preferably a compound having optical activity.
[0039]
[Usage]
The optical element according to the present invention includes, for example, an optical rotator, a wave plate, a polarizing plate, an optical deflector, a retardation plate, a waveguide, a lens, an optical fiber, and an optical fiber in the fields of an optical communication system, an optical switching system, and an optical measurement system. Coating materials, light emitting elements, light modulating elements, optical amplifying elements, optical switches, optical shutters, dimmers, dimming panels, magneto-optical storage elements, optical memories, holograms and other recording media, optical arithmetic elements, barcodes, It can be used for display materials such as solar cells, photodetectors, semiconductor lasers, solid-state lasers, LEDs, ELs, spatial light modulators, wavelength conversion elements, optical isolators, photorefractive, PSHB, liquid crystal panels, and head-up displays. .
It can be used as an optical modulation element utilizing the optical rotation, the driving frequency is preferably 1 MHz to 100 GHz, and the driving voltage is preferably 0.01 kV / m to 1 MV / m.
Further, since it has optical rotation in at least two axial directions, it can be used as a more advanced optical element such as an arithmetic element.
When used as an optical element, it can be used as a form combined with another optical element such as another polarizing plate.
[0040]
[shape]
The shape of the optical element according to the present invention is not particularly limited, but is usually a shape such as a molded article such as a rod, a film, a sheet, a fiber, a filament, a strand, or the like. The film used in the present specification refers to a thin flat plate-shaped molded article, refers to a film having a thickness of less than 0.25 mm, and the sheet refers to a film thicker than this. Fiber refers to an elongated linear solid. Further, it can be used as a molded product having a length to thickness ratio of 3 to 1 or more.
[0041]
[Molding method]
The optical element according to the present invention is manufactured by a known molding method, specifically, an injection molding method, an extrusion molding method, a blow molding method, an inflation molding method, a vacuum molding method, a melt film forming method, a dry film forming method. Method, wet film forming method, melt spinning method, dry spinning method, wet spinning method and the like.
[0042]
[Processing into film]
In the case of processing into a film shape, “a copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid”, for example, using an extruder equipped with a T die, a circular die or the like, An unstretched film can be formed. Further, if necessary, the obtained unstretched film can be uniaxially stretched, by sequential biaxial stretching method of roll stretching and tenter stretching, simultaneous biaxial stretching method by tenter stretching, biaxial stretching method by tubular stretching, etc. A biaxially stretched film can be produced by stretching.
For example, a stretched film by sequential biaxial stretching combining roll stretching and tenter stretching is produced as follows. A “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” is heat-treated at a temperature of 50 to 130 ° C., followed by drying and crystallization. Next, after melt-extruding at a temperature of 130 to 250 ° C. with an extruder equipped with a T die, the film is rapidly cooled with a casting roll of 60 ° C. or less to form a film. In this case, an air knife or an electrostatic application device is preferably used in order to improve the flatness by bringing the molten film into close contact with the roll. Next, the obtained film was passed through a take-up machine, and stretched 1.3 to 5 times, preferably 2 to 4 times at a temperature of 30 to 80 ° C. with a longitudinal stretching machine, and then 40 to 80 ° C. with a tenter. The film is stretched at a temperature of 1.3 to 5 times, preferably 2 to 4 times. When the stretched film needs to have heat resistance (heat shrinkage resistance), it is preferably subsequently heat-set in a tenter at a temperature of 80 to 150 ° C. for 3 to 120 seconds under tension.
[0043]
[Processing to fiber shape]
In the case of a fiber shape, it is kneaded and melted using an extruder or the like equipped with a spinning die and formed into a fiber through a spinneret. Furthermore, if necessary, the fiber can be stretched and oriented, and the oriented fiber can be annealed and further subjected to heat treatment. The spinning temperature may be higher than the melting point of the resin and lower than the decomposition temperature. Usually, it is preferably 120 ° C to 250 ° C. The stretching temperature is selected on the basis of the glass transition temperature of the fiber, but is usually preferably about 15 to 80 ° C. More preferably, it is 25-70 degreeC. The draw ratio is preferably 3 to 20 times in the length direction of the fiber, more preferably 3 to 10 times. The drawn fiber is preferably subjected to annealing and heat treatment in order to make the properties of tensile strength and dimensional stability uniform. The annealing is preferably performed for about 0.01 to 30 seconds at a temperature of 0.5 to 10% or under tension, preferably at 40 to 130 ° C. The heat treatment is preferably performed after annealing for 1 to 72 hours under tension under a reduced pressure of 40 to 150 ° C. and 130 to 100,000 Pa.
In order to obtain particularly high orientation, gel spinning method, liquid crystal spinning method, vibrational thermal stretching method, dielectric heating stretching method, two-stage stretching method (solid phase coextrusion, tensile stretching), stretching under pressure, zone heat treatment A method such as a method can be used.
The resin of the present invention thus obtained can be further processed by cutting, polishing or the like as required.
[0044]
[Other additives]
In the “copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid” used in the present invention, other additives than the above-mentioned additives may be added depending on the purpose. it can.
Specific examples of additives include, for example, plasticizers, heat stabilizers, light stabilizers, antioxidants, ultraviolet absorbers, pigments, colorants, various fillers, antistatic agents, mold release agents, fragrances, lubricants, difficulty Examples include a flame retardant, a foaming agent, a filler, an antibacterial agent, an antibacterial agent, and a nucleation agent.
[0045]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited only to an Example.
[0046]
[Production Example 1]
194.4 g of L-lactide, 17.4 g of glycolide and 0.022 g of tin octoate and 0.065 g of lauryl alcohol were charged into a thick cylindrical stainless steel polymerization vessel equipped with a stirrer, and were vacuumed for 2 hours. After degassing, it was replaced with nitrogen gas. The mixture was heated at 200 ° C. for 3 hours with stirring under a nitrogen atmosphere. While maintaining the temperature as it is, the inside of the reaction vessel was depressurized to 3 mmHg by gradually deaeration with a vacuum pump through an exhaust pipe and a glass receiver. One hour after the start of degassing, since the distillation of monomers and low molecular weight volatile components was stopped, the inside of the container was replaced with nitrogen, the polymer was extracted from the lower part of the container into a strand shape, pelletized, and a polylactic acid-glycolic acid copolymer Got. The weight average molecular weight Mw was 107,000.
[0047]
[Example 1]
The polylactic acid-glycolic acid copolymer obtained in Production Example 1 was melt extruded at 240 ° C. using an extruder and spun. The obtained fiber was stretched 5 times in the length direction at 50 ° C., and then annealed under tension at 60 ° C. for several seconds, and further heat-treated at 110 ° C. under reduced pressure for 3 hours.
When the optical rotation of this fiber was measured, it was 27 ° / 1 mm and had flexibility.
[0048]
[Example 2]
5 parts of cholesteryl bromide was mixed with 95 parts by weight of the polylactic acid-glycolic acid copolymer obtained in Production Example 1, and fibers were obtained in the same manner as in Example 1.
When the optical rotation of this fiber was measured, it was 78 ° / 1 mm and had flexibility.
[0049]
[Comparative Example 1]
When the optical rotation of quartz (α-SiO 2) was measured, it was 25 ° / 1 mm and there was no flexibility.
[0050]
【The invention's effect】
Light optical element obtained from the composition and the composition of the present invention, moldability, processability, flexibility, light weight, thin film properties, excellent in handling property, can be widely used in various fields.

Claims (22)

Weight of copolymer of lactic acid and (co) polymerizable polyfunctional compound other than lactic acid and cholesteric liquid crystal compound "copolymer of lactic acid and (co) polymerizable polyfunctional compound other than lactic acid" A composition comprising 0.001 to 30% by weight based on The composition according to claim 1, wherein the copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid includes a copolymer of lactic acid and a hydroxycarboxylic acid other than lactic acid . The copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid includes a copolymer of lactic acid and a polyhydric alcohol / polycarboxylic acid polymer . Composition. “(Co) polymerizable polyfunctional compounds other than lactic acid” include hydroxycarboxylic acids other than lactic acid, cyclic esters, polycarboxylic acids, polyhydric carboxylic acid anhydrides, polyhydric alcohols, polysaccharides, and amino acids. The composition according to claim 1, which is at least one selected from the group consisting of carboxylic acids . Hydroxycarboxylic acids other than lactic acid are glycolic acid, dimethyl glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, 2-hydroxyvaleric acid, 3- Hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 2-hydroxycaproic acid, 3-hydroxycaproic acid, 4-hydroxycaproic acid, 5-hydroxycaproic acid, 6-hydroxycaproic acid, 6-hydroxymethyl The composition according to claim 4, which is at least one selected from the group consisting of caproic acid and mandelic acid . The composition according to claim 4, wherein the cyclic ester is at least one selected from the group consisting of glycolide, β-methyl-δ-valerolactone, γ-valerolactone, and ε-caprolactone . The polyvalent carboxylic acid is at least selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and terephthalic acid The composition according to claim 4, which is a kind . The polyhydric alcohol is ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5- It consists of pentanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, tetramethylene glycol, and 1,4-hexanedimethanol. The composition according to claim 4, wherein the composition is at least one selected from the group . The composition according to claim 4, wherein the polysaccharide is at least one selected from the group consisting of cellulose and chemically modified cellulose .  The composition according to claim 4, wherein the aminocarboxylic acid is an α-amino acid. The isomer content in the lactic acid-derived repeating unit in "a copolymer of lactic acid and a (co) polymerizable polyfunctional compound other than lactic acid" is 0 to 10 mol%. A composition as described above . The composition according to any one of claims 1 to 11, wherein the cholesteric liquid crystal compound is a halogen compound of cholesterol. The composition according to any one of claims 1 to 12, which has an optical rotation . The composition according to claim 13, which has optical rotation in at least two axial directions . An optical element obtained from the composition according to claim 1. The optical element according to claim 15, wherein the optical element is a light modulation element. Driving frequency is 1MHz～100GHz, optical element according to claim 16. The optical element according to claim 16 or 17 , wherein the driving voltage is 0.01 kV / m to 1 MV / m . Optical elements that have a shape of a fiber according to either one of claims 15 to 18. Optical elements that have a shape of a film according to either one of claims 15 to 18. An optical element having the sheet shape according to claim 15 . Claims 15 to 18 length and thickness ratio is 3 to 1 or more moldings der Ru optical element according to any one of.