JP4066450B2 - Plasticizer for lactic acid resin and lactic acid resin composition - Google Patents

Description

【００５４】
【表２】

【００５５】
表２中可塑剤のトリアセチンは商品名 トリアセチン 大八化学工業（株）製、フタル酸ジメチルは商品名 ＤＭＰ 大八化学工業（株）製である。また、ガラス転移点温度において相溶せずとあるのは、トルクレオメーターにより得られた樹脂組成物が不均一であり、試験片の作成が困難であったことを示している。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasticizer for a non-chlorine resin and a plasticized resin composition.
[0002]
[Prior art]
Conventionally, plasticizers have been used to impart flexibility, durability, cold resistance, electrical properties, etc. to various plastics such as polyester, polyolefin, polyamide, polyacetal, vinyl resin, styrene resin, acrylic resin or cellulose resin. ing. Plasticizers are mainly used for vinyl chloride resins, and phthalic acid-based, fatty acid-based, phosphoric acid-based, and polyester-based plasticizers are known.
[0003]
By the way, plastics are used for various applications such as building materials, packaging materials and general goods because of their light weight and ease of molding. However, there are concerns about the effects of additives added to plastics on the human body and the environment, and the heat of combustion. There is a problem that the incineration treatment facility is bad due to its high price and it is difficult to biodegrade in the natural environment. In recent years, attention has been focused on the generation of toxic substances when burning specific chlorinated resins.
[0004]
As means for solving such problems, various biodegradable plastics have been proposed and commercial production has been carried out. Among them, polylactic acid, a kind of polyester, has been attracting attention for a long time because of its relatively good transparency. However, it is used in special fields such as medical applications because of its physical properties such as lack of price and flexibility. Stayed on.
[0005]
In terms of price, L-lactic acid, which is a raw material, has recently been manufactured at a low cost by a fermentation process, and mass production of polylactic acid is planned and a cost merit can be expected.
[0006]
On the other hand, although the improvement of the flexibility of polylactic acid has been achieved by the addition of various known plasticizers, problems such as insufficient plasticization effect and loss of transparency of the resin by the addition of plasticizer was there. Furthermore, some plasticizers are unsatisfactory due to concerns about impact on the human body and the environment, and the development of plasticizers that can reduce the environmental burden is eagerly desired.
[0007]
By the way, a plasticizer for vinyl chloride resin using a rosin derivative, which is a raw material derived from a natural product, has been studied (see Non-Patent Document 1). It is not something that can satisfy both of the above, is not widely used in general, and has not been studied since then. Moreover, although the lactic acid resin composition which mix | blended the rosin derivative (refer patent document 1) is disclosed, the said invention is for achieving the adhesive improvement effect, and is not touched at all about the plastic effect. It was.
[0008]
[Non-Patent Document 1]
Maejima, “Plasticizer: Ethylene glycol polymerized homologous series”, Occupational Chemical Journal, The Chemical Society of Japan, December 5, 1959, Vol. 62, No. 12, p. 1842-1845
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-49098
[Problems to be solved by the invention]
The present invention uses a compound obtained from a raw material derived from a natural product as a main raw material, a plasticizer for a lactic acid resin that can be expected to reduce the burden on the human body and the environment, and is excellent in flexibility and transparency. It aims at providing few lactic acid-type resin compositions.
[0010]
[Means for Solving the Problems]
The present inventors have found that by using a specific rosin derivative as a plasticizer to be blended into lactic acid based resin, thus completing the present invention that it is possible to solve the previous SL problems.
[0011]
That is, the present invention relates to (a) rosins, and (b) diethylene glycol, triethylene glycol, tetraethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether and polyethylene glycol (having an average polymerization degree of 3 to 7). A plasticizer for a lactic acid-based resin, which is a compound represented by the following general formula (1) obtained by reacting at least one compound selected from the group consisting of: Ro—COO — ((CHR ₁ ) ₁ (CHR ₂ ) _m —O) _n ((CHR ₃ ) _{1 ′} (CHR ₄ ) _{m ′} —O) _{n ′} —R ₅ (wherein Ro represents a rosin residue) _{, R 1, R 2, R} 3, R 4 is a hydrogen atom or a methyl group, _{R 5} is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, Sil group, l and l ′ are integers of 0 to 6, m and m ′ are integers of 0 to 6 (where 1 ≦ l + m ≦ 6, 1 ≦ l ′ + m ′ ≦ 6), and n and n ′ are 0 to 7 of an integer (where 1 ≦ n + n '≦ 7 ). according to).
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The plasticizer used in the present invention has the general formula (1): Ro—COO — ((CHR ₁ ) ₁ (CHR ₂ ) _m —O) _n ((CHR ₃ ) _{1 ′} (CHR ₄ ) _{m ′} —O) _{n '} -R ₅ (wherein, Ro is a rosin residue, R ₁ , R ₂ , R ₃ , R ₄ are a hydrogen atom or a methyl group, R ₅ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an acyl group) , L, l ′ are integers of 0-6, m, m ′ are integers of 0-6 (where 1 ≦ l + m ≦ 6, 1 ≦ l ′ + m ′ ≦ 6), n, n ′ are integers of 0-7 (Where 1 ≦ n + n ′ ≦ 7).) In the formula, when l + m, l ′ + m ′ exceeds 6, when n + n ′ exceeds 7, the compatibility with the resin deteriorates, and the transparency of the resulting resin composition deteriorates. Must be within range. Examples of the case where R is an acyl group include known ones such as an acetyl group and a benzoyl group, but particularly those represented by an acetyl group or Ro-CO (Ro represents rosin residues) are obtained. Since the transparency of the resin composition obtained becomes favorable, it is preferable.
Further, the plasticizer includes (a) rosins, and (b) diethylene glycol, triethylene glycol, tetraethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether and polyethylene glycol (having an average polymerization degree of 3 to 7). It is obtained by reacting at least one compound selected from the group consisting of: (c) ethylene oxide.

[0017]
(A) As rosins, natural rosins such as gum rosin, tall oil rosin, wood rosin; disproportionated rosin, hydrogenated rosin, dehydrogenated rosin, polymerized rosin, α, β-ethylenically unsaturated carboxylic acid modified rosin, etc. Examples of these modified rosins: purified natural rosin, purified rosin, and the like. Examples of the unsaturated carboxylic acid used in the preparation of the α, β-ethylenically unsaturated carboxylic acid-modified rosin include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, and acrylic acid. And methacrylic acid. Among these, at least one rosin selected from the group consisting of natural rosin, modified rosin, purified natural rosin and purified modified rosin is preferable. Among the rosins, it is particularly preferable to use at least one rosin selected from those having a high dehydroabietic acid content and derivatives thereof.
[0018]
The component (b), compatibility with the lactate-based resins, diethylene since plasticizing is good, triethylene glycol, tetraethylene glycol, triethylene glycol monoethyl ether or polyethylene glycol (average polymerization degree of 3 Triethylene glycol monomethyl ether, preferably n + n ′ is 3 to 7, triethylene glycol, tetraethylene glycol, triethylene glycol monoethyl ether or polyethylene glycol (average polymerization degree) 3 to 7) is preferable. In addition, the usage-amount of the said compound can be suitably selected with the seed | species of the target compound. That is, when R ₃ is a hydrogen atom, a plasticizer containing two rosin residues can be obtained by setting the carboxylic acid equivalent in component (a) / the hydroxyl equivalent in component (b) to 1/2 equivalent, If the equivalent of carboxylic acid in component (a) / hydroxyl equivalent in component (b) is 1/1 equivalent, a plasticizer containing one rosin residue can be obtained. When R ₅ is the general formula (4) Ro—CO— (Ro is a rosin residue), the carboxylic acid equivalent in component (a) / the hydroxyl equivalent in component (b) should be 1/1 equivalent. To obtain a plasticizer containing two rosin residues.
[0019]
A known esterification reaction method can be employed for the reaction between the component (a) and the component (b). Specifically, it is performed under conditions of high temperature of about 150 ° C. to 300 ° C. while removing generated water out of the system. In addition, if air is mixed in during the esterification reaction, the resulting esterified product may be colored. Therefore, the reaction is preferably performed under an inert gas such as nitrogen or helium. The reaction does not necessarily require an esterification catalyst, but in order to shorten the reaction time, acid catalysts such as acetic acid and paratoluenesulfonic acid, alkali metal hydroxides such as calcium hydroxide, calcium oxide, magnesium oxide, etc. It is also possible to use metal oxides.
[0020]
In particular, when the oxyalkylene chain of the esterified product to be prepared is long, the oxyalkylene chain portion is easily decomposed when the esterification reaction is carried out at a high temperature of about 150 ° C. to 300 ° C. Since it produces | generates, the target object is hard to be obtained. In that case, it is preferable to carry out the esterification reaction at a relatively low temperature by using a more reactive acid chloride as the rosin.
[0021]
Furthermore, after the esterification reaction of the component (a) and the component (b), the rosin residue can be modified.
[0022]
The component (c), using ethylene oxide in terms of compatibility is improved and the resulting lactic acid-based resin for plasticizer and acid-based resin (ethylene oxide). The amount of ethylene oxide used can be appropriately selected depending on the structure of the target compound. That is, when a plasticizer with a long alkylene chain is required, the compound may be reacted excessively, and when a plasticizer with a short alkylene chain is required, the compound may be reduced.
[0023]
For the reaction between the component (a) and the component (c), a conventionally known cyclic ether cleavage reaction method can be employed. For example, a catalyst such as an alkali metal hydroxide or alkoxide may be added, and the reaction may be performed at about 150 to 160 ° C. for about 1 to 5 hours under a pressurized condition of 7 to 9 × 10 ⁵ Pa as necessary. .
[0024]
When α, β-ethylenically unsaturated carboxylic acid-modified rosin is used as component (a), the carboxyl group with which component (b) or component (c) reacts is not limited to a carboxyl group derived from rosin, and α, It may be a carboxyl group derived from β-ethylenically unsaturated carboxylic acid, and all the carboxyl groups may be reacted with the component (b) or the component (c).
[0033]
As the lactic acid resin which can use the plasticizer of the present invention , any polyester resin obtained by polymerizing lactic acid can be used without any particular limitation. The lactic acid used for the polymerization may be L-form, D-form, or a mixture of L-form and D-form. In addition, when using the mixture of L-form and D-form, the use ratio of L-form and D-form can be arbitrarily determined according to the intended purpose. The lactic acid-based resin is not limited to a polylactic acid homopolymer, but may be a copolymer, a blend polymer, or the like. Examples of the components that form the copolymer include hydroxycarboxylic acids such as glycolic acid, 3-hydroxybutyric acid, 5-hydroxyvaleric acid, and 6-hydroxycaproic acid, succinic acid, adipic acid, sebacic acid, glutaric acid, and decane. Dicarboxylic acid typified by dicarboxylic acid, terephthalic acid, isophthalic acid, etc., polyhydric alcohol typified by ethylene glycol, propanediol, octanediol, dodecanediol, glycerin, sorbitan, polyethylene glycol, glycolide, ε-caprolactone, δ -Lactones represented by butyrolactone are mentioned. Examples of the polymer blended with polylactic acid include cellulose, cellulose nitrate, methyl cellulose, regenerated cellulose, glycogen, chitin, and chitosan.
[0035]
The amount of the plasticizer used is 1 to 300 parts by weight, preferably 5 to 150 parts by weight, and more preferably 10 to 100 parts by weight with respect to 100 parts by weight of the lactic acid resin. The use in such a range, improves the flexibility of the lactic acid resin, without impairing transparency, less temporal property decrease, preferably possible to provide a lactic acid-based resin composition. If necessary, two or more kinds of plasticizers presented in the present invention and conventionally known plasticizers may be used simultaneously.
[0036]
The method for blending the plasticizer presented in the present invention with the lactic acid resin is not particularly limited, but is a method of mixing with an ordinary blender or mixer, a method of melt-kneading using an extruder, a Banbury mixer, etc. Is mentioned. Moreover, you may mix the plasticizer shown by this invention from the step of the polymerization reaction process of lactic acid-type resin.
[0037]
Note that the lactic acid resin composition obtained using the plasticizer of the present invention includes a crystal nucleating agent other than the plasticizer, an antistatic agent, a foaming agent, a heat stabilizer, a light stabilizer, a weather stabilizer, a lubricant, Various compounding agents such as a release agent, an inorganic filler, a pigment dispersant, a pigment, and a dye may be contained within a range that does not impair the object of the present invention.
[0038]
The lactic acid resin composition obtained by using the plasticizer for lactic acid resin of the present invention is formed by extrusion molding, injection molding, stretched film molding, blow molding and the like, as with general thermoplastics. The method can be used for a wide range of applications from household goods to industrial goods, such as food containers, electrical parts, electronic parts, automobile parts, mechanical mechanism parts, films, sheets, fibers, etc. The
[0039]
【The invention's effect】
The plasticizer for lactic acid-based resins of the present invention is mainly made of rosin, which is a natural product, and exhibits a plastic effect when added to the resin. In addition, the obtained lactic acid-based resin composition has transparency, flexibility and little change with time, has better biodegradability than conventional general-purpose plastics, and has low combustion heat, Useful for solving garbage disposal problems.
[0040]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
[0041]
Example 1
In a 1 liter pressure vessel equipped with a stirrer, rosin (containing about 50% dehydroabietic acid) (trade name: KR-85 manufactured by Arakawa Chemical Industries, Ltd.) 302.0 g (1.0 mol), sodium methoxide 2. 2 g (0.04 mol) was added, 88.0 g (2.0 mol) of ethylene oxide was added thereto, and the mixture was stirred for 1 hour at 150 to 160 ° C. while maintaining a pressure of 7 to 9 × 10 ⁵ Pa. Turned into. Sodium methoxide was removed to obtain 390.0 g of diethylene glycol rosin ester.
[0042]
Example 2
Into a 1 liter reaction vessel equipped with a condenser and a stirrer, 384.0 g (1.0 mol) of diethylene glycol rosin ester prepared by the method of Example 1 and 150.0 g of toluene were placed, and toluene was refluxed at 180 ° C. for 1 hour. The water in the system was removed. After toluene was distilled off, 204.2 g (2.0 mol) of acetic anhydride was added dropwise and stirred at 140 ° C. for 3 hours for acetylation. Unreacted matter was distilled off under reduced pressure to obtain 424.7 g of diethylene glycol rosin ester acetate.
[0043]
Example 3
In a 1 liter pressure vessel equipped with a stirrer, rosin (containing about 80% dehydroabietic acid) (trade name KR-614, Arakawa Chemical Industries, Ltd.) 302.0 g (1.0 mol), sodium methoxide 2. 2 g (0.04 mol) was added, 132.0 g (3.0 mol) of ethylene oxide was added thereto, and the mixture was stirred at 150 to 160 ° C. for 1 hour while maintaining a pressure of 7 to 9 × 10 ⁵ Pa. Turned into. Sodium methoxide was removed to obtain 434.0 g of triethylene glycol rosin ester.
[0044]
Example 4
In a 1 liter pressure vessel equipped with a stirrer, rosin (containing about 80% dehydroabietic acid) (trade name KR-614, Arakawa Chemical Industries, Ltd.) 302.0 g (1.0 mol), sodium methoxide 2. 2 g (0.04 mol) was added, 176.0 g (4.0 mol) of ethylene oxide was added thereto, and the mixture was stirred at 150 to 160 ° C. for 1 hour while maintaining a pressure of 7 to 9 × 10 ⁵ Pa. Turned into. Sodium methoxide was removed to obtain 478.0 g of tetraethylene glycol rosin ester.
[0045]
Example 5
Add rosin (containing about 80% dehydroabietic acid) (trade name: KR-614, Arakawa Chemical Co., Ltd.) 392.6 g (1.3 mol) to a 1 liter reaction vessel equipped with a condenser and a stirrer and heat. This was melted, and 234.8 g (1.43 mol) of triethylene glycol monomethyl ether and 2.4 g of triphenyl phosphite (0.6 parts by weight with respect to 100 parts by weight of KR-614) were added at 150 ° C. for 15 minutes. And dripped. After completion of dropping, the temperature was raised to 280 ° C. and stirred for 19 hours. Unreacted product was distilled off under reduced pressure to obtain 566.8 g of triethylene glycol monomethyl ether rosin ester.
[0046]
Example 6
Add rosin (containing about 80% dehydroabietic acid) (trade name: KR-614, Arakawa Chemical Co., Ltd.) 392.6 g (1.3 mol) to a 1 liter reaction vessel equipped with a condenser and a stirrer and heat. 254.8 g (1.43 mol) of triethylene glycol monoethyl ether and 2.4 g of triphenyl phosphite (0.6 parts by weight with respect to 100 parts by weight of KR-614) were melted at 150 ° C. for 15 minutes. It was dripped over. After completion of dropping, the temperature was raised to 280 ° C. and stirred for 19 hours. Unreacted product was distilled off under reduced pressure to obtain 584.8 g of triethylene glycol monoethyl ether rosin ester.
[0047]
Example 7
Add 302.0 g (1.0 mol) of rosin (containing about 80% dehydroabietic acid) (trade name: KR-614, Arakawa Chemical Co., Ltd.) to a 1 liter reaction vessel equipped with a condenser and a stirrer. After melted, 374.9 g (1.8 mol) of polyethylene glycol (average polymerization degree 4) (trade name: PEG200, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added dropwise at 150 ° C. over 30 minutes, and then triphenylphosphine was added. 1.8 g of Fight (0.6 parts by weight with respect to 100 parts by weight of KR-614) was added dropwise. After completion of dropping, the temperature was raised to 280 ° C. and stirred for 23 hours. Unreacted material was distilled off under reduced pressure to obtain 505.0 g of PEG200 rosin ester.
[0048]
Example 8
Add 302.0 g (1.0 mol) of rosin (containing about 80% dehydroabietic acid) (trade name: KR-614, Arakawa Chemical Co., Ltd.) to a 1 liter reaction vessel equipped with a condenser and a stirrer. After melting, 545.4 g (1.8 mol) of polyethylene glycol (average polymerization degree 6) (trade name: PEG300, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added dropwise thereto at 150 ° C. over 45 minutes, and then triphenylphosphine was added. 1.8 g of Fight (0.6 parts by weight with respect to 100 parts by weight of KR-614) was added dropwise. After completion of dropping, the temperature was raised to 280 ° C. and stirred for 23 hours. Unreacted material was distilled off under reduced pressure to obtain 605.0 g of PEG300 rosin ester.
[0049]
Comparative Example 1
Octaethylene glycol rosin ester was obtained in the same manner as in Example 1 except that the amount of ethylene oxide was 352.0 g (8 mol).
[0050]
(Evaluation Examples 1 to 8 and Comparative Evaluation Examples 1 to 4)
The amount shown in Table 1 or Table 2 was set by adding the plasticizers obtained in Examples and Comparative Examples to 100 parts by weight of polylactic acid (trade name LACTY 9031, Shimadzu Corporation weight average molecular weight 140,000, melting point 133 ° C.). A predetermined amount was melt-kneaded with a Brabender torque rheometer (Plasticcoder PL-2000) at a temperature of 190 ° C. to obtain a resin composition. Using this resin composition, a test piece was prepared by compression molding at a melting temperature of 170 ° C. and a cooling temperature of 20 ° C. The test piece was evaluated for transparency and glass transition temperature.
[0051]
(transparency)
Judgment was made by visual evaluation. ○: No turbidity, ×: Turbidity results are shown in Tables 1 and 2.
[0052]
(Flexibility)
An index was obtained by measuring the glass transition temperature. If the glass transition temperature is lower than the ambient temperature, the resin composition can be said to be in a rubber state, that is, a flexible state.
The glass transition temperature was measured with a DSC (differential scanning calorimeter DSC220C) manufactured by Seiko Denshi.
[0053]
[Table 1]

[0054]
[Table 2]

[0055]
In Table 2, the plasticizer triacetin is a trade name Triacetin manufactured by Daihachi Chemical Industry Co., Ltd., and dimethyl phthalate is a trade name DMP manufactured by Daihachi Chemical Industry Co., Ltd. Further, the fact that they are not compatible at the glass transition temperature indicates that the resin composition obtained by the torque rheometer is non-uniform and it is difficult to prepare a test piece.

Claims (1)

From the group consisting of (a) rosins, and (b) diethylene glycol, triethylene glycol, tetraethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether and polyethylene glycol (having an average polymerization degree of 3 to 7) A plasticizer for a lactic acid resin comprising a compound represented by the following general formula (1) obtained by reacting at least one selected compound or (c) ethylene oxide.
General formula (1): Ro—COO — ((CHR ₁ ) ₁ (CHR ₂ ) _m —O) _n ((CHR ₃ ) _{1 ′} (CHR ₄ ) _{m ′} —O) _{n ′} —R ₅ (wherein Ro is a rosin residue, R ₁ , R ₂ , R ₃ and R ₄ are a hydrogen atom or a methyl group, R ₅ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an acyl group, l and l ′ are 0 to 0 An integer of 6, m and m ′ are integers of 0 to 6 (where 1 ≦ l + m ≦ 6, 1 ≦ l ′ + m ′ ≦ 6), and n and n ′ are integers of 0 to 7 (where 1 ≦ n + n ′ ≦ 7) )