JP2000129035A - Resin composition and molding prepared therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition having moldability and giving a molding having a sufficiently practical heat resistance temperature, solvent resistance, biodegradability, and high mechanical strengths and to provide a molding prepared therefrom. SOLUTION: This composition comprises (A) a polymer having a highly transparent cellulose ester structure and (B) a polymer having an aliphatic ester structure having high flexibility, hydrolysis resistance, and biodegradability in an A/B ratio of 5/95 to 95/5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition comprising a polymer (A) having an aliphatic ester structure and a polymer (B) having a cellulose ester structure, and a molded product thereof.

The resin composition comprising the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure according to the present invention has transparency, excellent flowability and moldability. , Injection molding, Extrusion molding, Inflation molding, Vacuum pressure molding, Blow molding,
Suitable for obtaining fibers, multifilaments, monofilaments, ropes, nets, woven fabrics, knitted fabrics, nonwoven fabrics, films, sheets, laminates, containers, foams, various parts and other molded products, and the obtained molded products are sufficient machines It has strong strength and heat resistance, and is easily decomposed by microorganisms in soil, activated sludge, and compost. Therefore, it can be widely used for packaging materials, agriculture, fisheries, foods, and other applications where recycling is difficult. In particular, since it has physical properties close to that of vinyl chloride, its use as a substitute is expected.
For example, in the field of packaging materials, various types of packaging are possible as films, and heat sealing is also possible. In the agricultural field, it can be used as a multi-film that covers the soil surface to keep the soil warm, a pot or string for planting, or a fertilizer coating material, or in the fishery field for fishing lines, fish nets, and medical use in the medical field. It can be used as a sanitary material for materials and sanitary products.

[0003]

2. Description of the Related Art In recent years, there has been a demand for the development of a polymer material which can be decomposed in a natural environment in response to environmental problems on a global scale. Great expectations are placed on compatible materials and new types of functional materials.

It has been well known that a polymer having an aliphatic ester structure has biodegradability, and poly-3-hydroxybutyrate (PHB) produced by microorganisms and poly (polymer) which is a synthetic polymer have been known. Caprolactone (P
CL), polybutylene succinate (PBS) containing succinic acid and butanediol as main components, and polylactic acid (PLLA) using L-lactic acid produced by fermentation as a raw material. Further, the present inventors have conducted intensive studies, and as a result, have been disclosed in JP-A-7-53693 and JP-A-7-5-5.
No. 3695 discloses a biodegradable polyester carbonate having high thermal stability, excellent fluidity and moldability, and sufficient mechanical strength, and a method for producing the same.

[0005] On the other hand, a polymer having a cellulose ester structure is mainly derived from petroleum-independent raw materials and is considered to be a material having a low environmental load. It is an excellent material with high transparency. Conventionally, biodegradability of cellulose acetate having a low degree of substitution has been confirmed, and further application development has been desired.

[0006] A polymer having an aliphatic ester structure is generally a polymer having properties similar to polyethylene and having good moldability and biodegradability, except for polylactic acid. However, in fields where transparency is required, it has been desired to impart transparency.

As described above, although the existing plastics have their respective characteristics, there are many insufficient parts, and it is desired to develop a plastic having a good balance of strength, heat resistance, moldability, transparency and biodegradability. I was

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition having a practically sufficient heat-resistant temperature, moldability, solvent resistance, biodegradability and high mechanical strength, and a molded article thereof. To provide.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a polymer having a cellulose ester structure having high transparency, flexibility, hydrolysis resistance and biodegradability By mixing with a polymer having a high aliphatic ester structure, the resin has a heat distortion temperature sufficient for practical use, and has transparency, moldability, heat resistance, solvent resistance and mechanical strength It has been found that a composition and a molded article thereof can be obtained. In addition, when the compatibility between the polymer having a cellulose ester structure and the polymer having an aliphatic ester structure is low, by blending a compatibilizer, it has a heat distortion temperature sufficient for practical use, It has been found that a resin composition having transparency, moldability, heat resistance, solvent resistance and mechanical strength and a molded article thereof can be obtained.

That is, the present invention provides a resin composition comprising a polymer having an aliphatic ester structure (A) and a polymer having a cellulose ester structure (B), a molded article thereof, and a polymer having an aliphatic ester structure. The present invention relates to a resin composition comprising a coalesced compound (A), a polymer (B) having a cellulose ester structure, and a compatibilizer (C), and a molded article thereof.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer (A) having an aliphatic ester structure in the present invention includes poly-3-hydroxybutyrate (PHB) and polycaprolactone (PC
L), aliphatic polyesters such as polybutylene succinate (PBS) or polybutylene succinate adipate containing succinic acid and butanediol as main components, and polylactic acid (PLLA) containing L lactic acid as a main raw material, and aliphatic polyesters Examples thereof include carbonate. Among them, polybutylene succinate, polybutylene succinate adipate or aliphatic polyester carbonate has high compatibility with a polymer having a cellulose ester structure, and is particularly preferable.

The aliphatic polyester carbonate in the present invention refers to a number average molecular weight of 10,000 or less obtained by reacting an aliphatic dibasic acid and / or a derivative thereof with an aliphatic dihydroxy compound and / or a hydroxycarboxylic acid compound. An aliphatic polyester oligomer of
The carbonate unit content obtained by reacting with a carbonate compound is at least 5 mol%, the weight average molecular weight is at least 100,000, and the temperature is 190
Melt viscosity at ℃, 60kg load is 2,000-5
It has a melting point of 70 to 180 ° C. at 0000 poise.

The process for producing an aliphatic polyester carbonate according to the present invention comprises a first step of obtaining an aliphatic polyester oligomer from an aliphatic dibasic acid and / or a derivative thereof and an aliphatic dihydroxy compound and / or a hydroxycarboxylic acid compound, and It comprises a second step of reacting the aliphatic polyester oligomer with a carbonate compound to obtain an aliphatic polyester carbonate.

The first step is carried out in the presence of a catalyst at a temperature of 100 to 100.
At 250 ° C., while removing water and excess dihydroxy compound produced as a by-product of the reaction, the number average molecular weight was 10,000.
This is a step of producing a polyester oligomer of 0 or less. It is preferable to reduce the pressure to 300 mmHg or less for the purpose of promoting the reaction.

The second step is a step in which the polyester oligomer obtained in the first step is reacted with a carbonate compound to obtain a high molecular weight compound.
The reaction is carried out at ２５０250 ° C. to remove by-product hydroxy compounds accompanying the reaction. Depending on the boiling point of the carbonate compound, the pressure is increased at the beginning of the reaction. Preferably, the degree of pressure reduction is adjusted to finally reduce the pressure to 3 mmHg or less.

The content of the carbonate unit in the aliphatic polyester carbonate can be controlled to a desired ratio by controlling the amount of terminal hydroxyl groups of the aliphatic polyester oligomer. If the carbonate unit content is too large,
The melting point of the aliphatic polyester carbonate obtained is low, and a polymer having practical heat resistance cannot be obtained. On the other hand, when the carbonate unit content increases, the degradability by microorganisms increases. Therefore, the carbonate unit content, it is preferable to have an appropriate biodegradability, and it is preferable to be an amount that can achieve practical heat resistance, in the present invention, the carbonate unit content in the aliphatic polyester carbonate, It is preferably at least 5 mol% or more, usually 5 to 30 mol%.

As the aliphatic dibasic acid used in the production of the aliphatic polyester carbonate of the present invention, succinic acid is used as an essential component. In addition, oxalic acid, malonic acid, glutaric acid, adipic acid, suberin acid,
Sebacic acid, dodecanoic acid, azelaic acid and the like can be appropriately used in combination. The above aliphatic dibasic acids may be esters or acid anhydrides thereof.

The aliphatic dihydroxy compound used for producing the aliphatic polyester carbonate of the present invention is 1,1.
4-butanediol is used as an essential component, and for example, ethylene glycol, trimethylene glycol, propylene glycol, 1,3-butanediol, pentanediol, hexanediol, octanediol, neopentylglycol, cyclohexanediol, cyclohexane Dimethanol or the like can be used in combination as appropriate.

Examples of the hydroxycarboxylic acid compound used in the present invention include lactic acid, glycolic acid, β-hydroxybutyric acid, hydroxypivalic acid, hydroxyvaleric acid and the like. These can also be used as derivatives such as esters and cyclic esters. .

These aliphatic dibasic acids, aliphatic dihydroxy compounds and hydroxycarboxylic acid compounds can be used alone or as a mixture, and can be combined in any desired manner. It is preferable that the material has a melting point and a melting point high enough to realize practical heat resistance. Therefore, in the present invention, 1,4-butanediol is used as an aliphatic dihydroxy compound, and succinic acid is used as an aliphatic dibasic acid.
It is necessary to contain 0 mol% or more.

Specific examples of the carbonate compound used in the production of the aliphatic polyester carbonate of the present invention include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m
-Diaryl carbonates such as cresyl carbonate, and aliphatic carbonate compounds such as dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, dibutyl carbonate, diamyl carbonate, and dioctyl carbonate, but are not limited thereto. . In addition to the above-mentioned carbonate compound composed of the same type of hydroxy compound, an asymmetric carbonate compound or a cyclic carbonate compound composed of a different type of hydroxy compound can also be used.

In the present invention, the polymer (B) having a cellulose ester structure means generally commercially available cellulose acetate, cellulose acetate propionate,
Cellulose acetate butyrate or a mixture of two or more selected from them is used. The substitution degree of the polymer (B) having a cellulose ester structure is 1.0 to 3.0.
0 is preferable, and more preferably 1.5 to 3.0,
Particularly preferably, it is 2.0 to 3.0. The content of the propionyl group and the butyryl group in the cellulose acetate propionate and the cellulose acetate butyrate is 1 to 80% based on the substitutable site. Although the compatibility changes depending on the molecular weight and the raw material monomer,
If the compatibility is insufficient, a compatibilizer can be added.

The compatibilizer in the present invention is added for the purpose of improving the compatibility between the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure. Examples of the compatibilizer used in the present invention include diethyl phthalate, triphenyl phosphate, butyl phthalyl butyl glycolate, and triacetin. In particular, triacetin is preferred from the viewpoint of improving transparency. The compounding amount is 1 to 100 parts by weight of the total of the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure.
-30 parts by weight are preferred.

In order to obtain a resin composition having high biodegradability, it is preferable to keep the substitution degree of the cellulose ester low. However, in the case of the present invention, a high substitution degree which is conventionally considered to have low biodegradability is preferred. Biodegradability can be easily expressed even with cellulose esters. In addition, it has transparency and sufficient mechanical strength, and is considered to be a substitute for vinyl chloride.

The resin composition of the present invention mainly comprises the above-mentioned polymer (A) having an aliphatic ester structure, the polymer (B) having a cellulose ester structure and, if necessary, a compatibilizer (C). , Modifiers, fillers, lubricants, ultraviolet absorbers, antioxidants, stabilizers, pigments, colorants, various fillers, antistatic agents, mold release agents, plasticizers, fragrances, antibacterial agents, etc. Can be blended. Furthermore, various monomers, coupling agents, terminal treating agents, other resins, wood flour, starch and the like can be added for modification.

In the production, it can be obtained by mechanically mixing at a temperature higher than the melting temperature of at least one resin. Also, a method of manufacturing by mixing and pressing both resins mechanically pulverized, or by dissolving both resins in a solvent and then mixing with a poor solvent to obtain a precipitate, or by mixing both resins in a solvent. It is also possible to produce the polymer by casting the dissolved product and removing the solvent, but it is not limited thereto. The mixing device is not particularly limited, but is industrially recommended because a method of mixing using an extruder can be continuously processed in a short time.

When the temperature at the time of mixing is 100 ° C. or lower, the melt viscosity of the resin is high or the resin does not melt.
A range from 00 degrees to 300 degrees is preferred. If the temperature is 300 degrees or more, thermal decomposition of the resin occurs, which is not preferable. Even at a temperature of 300 ° C. or less, it is preferable to mix the mixture in a short time under a nitrogen atmosphere in order to prevent coloring, deterioration, thermal decomposition, and the like at a high temperature. It is recommended that a specific mixing time be within 20 minutes. In addition, a vent may be provided for removing oligomers, residual monomers, generated gas, and the like in the resin, and mixing may be performed under reduced pressure.

The resin composition of the present invention is not limited to a simple blend of the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure, but may be prepared in the presence of a catalyst. And a copolymer formed by a transesterification reaction or the like in a molten state. Further, a production method in which the polymer (A) having an aliphatic ester structure is added in the ester substitution step of the polymer (B) having a cellulose ester structure can also be adopted.

The mixing ratio of the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure is preferably in the range of 95/5 to 5/95 by weight of A / B. is there. If the amount of the polymer (A) having an aliphatic ester structure is 5% or less, the value of tensile elongation of 5% cannot be achieved, resulting in poor film moldability and insufficient biodegradability. If the blending amount of the polymer (B) having a cellulose ester structure is 5% or less, transparency and bending strength of 20 MPa or more cannot be achieved. The molecular weight of the resin used here is desirably 100,000 or more as a weight average molecular weight by GPC in terms of styrene. If it is less than 100,000, the desired strength cannot be achieved.

When the proportion of the polymer (A) having an aliphatic ester structure is high, the biodegradability and tensile elongation are high, and when the proportion of the polymer (B) having a cellulose ester structure is high, the transparency is high. Because of the increase, it is possible to design a resin according to the application and purpose.

The molded article of the present invention is an article molded using the resin composition of the present invention. Specific molding forms and molding methods include an injection molded article, an extrusion molded article, an inflation molding method, and a vacuum molding method. Compressed air products, blow molded products, fibers, multifilaments, monofilaments, ropes,
Examples include, but are not limited to, nets, wovens, knits, nonwovens, films, sheets, laminates, containers, foams, various parts, and other molded articles. In particular, the resin composition of the present invention has good film moldability, and the polymer (B) having a cellulose ester structure is generally improved, whereas the film moldability is usually poor. From the viewpoint of uniformity, strength, appearance and the like of the resin, it is preferable that the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure are mixed and pelletized before molding. The polymer (A) having a structure and the polymer (B) having a cellulose ester structure may be mixed in a pellet state with various additives at the same time, and then directly added to a molding machine to obtain a molded product. Furthermore, it is also possible to obtain a film, sheet or other molded product by dissolving both resins in a solvent, casting or applying the solution in a solution state, and removing the solvent.

The resin composition and the molded article of the present invention have high mechanical strength and a practically sufficient softening temperature, and are easily decomposed by microorganisms in soil, activated sludge, and compost.

The biodegradability of the resin composition and the molded article of the present invention is determined by the polymer (A) having a molecular weight and an aliphatic ester structure.
The ratio can be adjusted by the mixing ratio of the polymer and the polymer (B) having a cellulose ester structure, and the thickness of the molded article, and shows a decomposability of 60% or more in a compost test using a powder.

As described above, according to the present invention, it is possible to provide a resin composition from which molded articles having practically sufficient transparency, heat resistance, strength and biodegradability can be obtained.

[0035]

The resin composition comprising the polymer having an aliphatic ester structure (A) and the polymer having a cellulose ester structure (B) according to the present invention has excellent transparency, fluidity and moldability. , Injection molding, extrusion molding, vacuum pressure molding, blow molding, fiber, multifilament, monofilament, rope, net, woven, knitted, nonwoven, film, sheet, laminate, container, foam, various parts, etc. It is suitable for obtaining a molded article, and the obtained molded article has sufficient mechanical strength and heat resistance and is easily decomposed by microorganisms in soil, activated sludge, and compost. Therefore, it can be widely used for packaging materials, agriculture, fisheries, foods, and other applications where recycling is difficult. For example, in the field of packaging materials, various types of packaging are possible as films, and heat sealing is also possible. In the agricultural field, it can be used as a multi-film that covers the soil surface to keep the soil warm, a pot or string for planting, or a fertilizer coating material, or in the fishery field for fishing lines, fish nets, and medical use in the medical field. It can be used as a sanitary material for materials and sanitary products.

[0036]

Next, the present invention will be described in more detail by way of examples. In this example, the melting point was measured using DSC (SSC 5000 manufactured by Seiko Instruments Inc.). The molecular weight was measured as Mw and Mn in terms of styrene by GPC (using GPC System-11 manufactured by Showa Denko KK) using chloroform as a solvent. The carbonate unit content is determined by NMR (NMR, manufactured by JEOL Ltd.).
EX-270), and was measured by ¹³ C-NMR as a ratio (mol%) of a carbonate unit to a total of a dicarboxylic acid ester unit and a carbonate unit.

The melt viscosity was measured using a flow tester (CFT-500C manufactured by Shimadzu Corporation) at a temperature of 190 ° C. under a load of 60 k.
g. The hydroxyl value and acid value of the oligomer of the aliphatic polyester carbonate were measured according to JIS K-1557.

Aliphatic polyester carbonate (PE
Production Example 1 of C) 18,740 g of succinic acid was placed in a 50-liter reaction vessel equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube.
(158.7 mol), 1,4-butanediol 21,4
30 g (237.8 mol), 745 mg of zirconium acetylacetonate and 1.40 g of zinc acetate were charged and reacted under a nitrogen atmosphere at a temperature of 150 to 220 ° C. for 2 hours to distill water. Then, the degree of decompression is 150-80 mm
Aging was performed for 3 hours at a reduced pressure of Hg to advance the dehydration reaction, and finally the pressure was gradually increased to a pressure of 2 mmHg or less to further distill water and 1,4-butanediol. The reaction was stopped when the amount reached 10,460 g. The number average molecular weight of the obtained oligomer is 1,7.
80, the terminal hydroxyl value was 102 KOH mg / g, and the acid value was 0.51 KOH mg / g.

Next, 24,000 g of the obtained oligomer was charged into a 50-liter reaction vessel equipped with a stirrer, a distillation condenser, a thermometer, and a gas inlet tube, and 4,680 g of diphenyl carbonate was added. Temperature 210-220 ° C
Finally, the pressure was reduced to 1 mmHg, and the reaction was carried out for 5 hours to produce an aliphatic polyester carbonate (PEC). The obtained PEC has a melting point of 104 ° C., a weight average molecular weight (Mw) measured by GPC of 188,000, and ¹³ C-
According to NMR measurement, 14.
It had 3% carbonate units. Melt viscosity is 1
It was 0000 poise, completely dissolved in chloroform, and had no gel component.

Example of Use of Polymer Having Cellulose Ester Structure The following polymer having a cellulose ester structure was used. Cellulose diacetate (CDA): degree of substitution 2.4-2.5 Average degree of polymerization 160 Cellulose acetate propionate (CAP): degree of substitution 1.4-1.5 Acetyl Content 2.5% Propionyl Content 45-49% Cellulose acetate butyrate (CAB): degree of substitution 1.4 to 1.7 Acetyl Content 12 to 15% Butyryl Content 35 to 39%

Example 1 Pellets of the PEC obtained in Production Example 1 and the polymer (CDA) having a cellulose ester structure shown in the usage example were dried at 90 ° C. for 10 hours by a vacuum dryer. The CDA and PEC subjected to this drying treatment are 90/10 by weight ratio.
Using 15% by weight of triacetin (TA) based on the total amount of CDA and PEC, each was mixed in a V-type blender, and a twin screw extruder (screw diameter 25 mm) was used.
(φ, L / D = 30) and continuously formed into a strand and pelletized to obtain a resin mixture. After the pellets of the resin mixture were dried at a temperature of 90 ° C. for 5 hours or more, the pellets were supplied to an injection molding machine (mold clamping pressure: 1000 tons) to mold a test piece for a physical property test. As a result of the evaluation of the obtained test piece, the tensile elongation was 37%, the tensile strength was 44.3 MPa, and the Young's modulus was 1308 MPa, which was transparent. Small amount of PEC
Despite the use of, the film formability was significantly improved. Table 1 shows the physical property evaluation results.

Examples 2 to 5 Results of evaluation of physical properties when PEC and CDA were changed by the same operation as in Example 1 at a weight ratio of 30/70, 50/50, 70/30, 90/10. Example 2
Table 1 shows the results.

Examples 6 and 7 The CAP and CAP shown in the usage example were operated in exactly the same manner as in Example 1.
Physical properties were evaluated using CAB and PEC at a ratio of 70/30. The results are shown in Table 1. Good physical properties were shown even though no compatibilizer was added.

Comparative Examples 1 and 2 Table 1 shows the results obtained by performing exactly the same operation as in Example 1 for 100% of CDA, as Comparative Example 1, and performing the same operation with 100% of PEC as Comparative Example 2. . CDA 100%
In this case, the processability was poor and the measurement was performed with the addition of triacetin, but the biodegradability was low. In addition, PEC10
At 0%, biodegradability is good, but transparency is not exhibited.

The resin mixtures prepared in Examples 1 to 7 and Comparative Examples 1 and 2, the aliphatic polyester carbonate and the polymer having a cellulose ester structure were each formed into a 150 μm-thick sheet at 25 ° C. and 60% RH. A soil burial test was performed under the conditions. Each sample was cut into 20 × 90 mm and buried 5 cm deep from the soil surface. During 18 weeks, changes such as disappearance of these resin samples due to decomposition and opening of holes due to decomposition were observed. Table 1 shows the weight change of the sample. This indicates that when the content of the polymer having an aliphatic ester structure is increased, the biodegradability is improved, and the rate of biodegradation is easily adjusted.

[0046]

[Table 1]

Claims (8)

[Claims] 1. A polymer (A) having an aliphatic ester structure
And a polymer (B) having a cellulose ester structure, wherein the weight ratio of the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure is A /
A resin composition wherein B = 95/5 to 5/95. 2. A polymer (A) having an aliphatic ester structure
And a polymer (B) having a cellulose ester structure and a compatibilizer (C), and the weight ratio of the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure is as follows: A / B = 95 / 5-5 / 95,
A resin composition wherein the compatibilizer (C) is 1 to 30 parts by weight based on 100 parts by weight of the total of the polymer (A) having an aliphatic ester structure and the polymer (B) having a cellulose ester structure. 3. The resin composition according to claim 1, wherein the polymer (A) having an aliphatic ester structure is an aliphatic polyester carbonate and / or an aliphatic polyester. 4. The polymer according to claim 1, wherein the polymer (B) having a cellulose ester structure is cellulose acetate, cellulose acetate propionate or cellulose acetate butyrate having a degree of substitution of 1.0 to 3.0. Resin composition. 5. The resin composition according to claim 2, wherein the compatibilizer (C) is triacetin. 6. A heat deformation temperature of 80 ° C. or more and a tensile elongation of 5%.
As described above, the tensile strength is 20 MPa or more and the Young's modulus is 20
The resin composition according to claim 1, which has a pressure of 0 MPa or more. 7. An aliphatic polyester carbonate (A)
Is a number average molecular weight of 10.0 obtained by reacting an aliphatic dibasic acid and / or a derivative thereof with an aliphatic dihydroxy compound and / or a hydroxycarboxylic acid compound.
The carbonate unit content obtained by reacting an aliphatic polyester oligomer having a molecular weight of not more than 00 with a carbonate compound is at least 5 mol%, the weight average molecular weight is at least 100,000, the temperature is 190 ° C., and the load is 6
The resin composition according to claim 1, wherein the resin composition has a melt viscosity at 0 kg of 2,000 to 50,000 poise and a melting point of 70 to 180 ° C. 4. 8. A molded article obtained by molding the composition according to claim 1 or 2.