JP2002097358A - Biodegradable ligneous aliphatic polyester resin composition and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a biodegradable ligneous aliphatic polyester resin composition that has excellent mechanical performance, biodegradability and processability of molding. SOLUTION: The objective biodegradable polyester is obtained by formulating 30-200 pts.wt. of an organic filler, 0.1-7 pts.wt. of a lubricant and/or 1-50 pts.wt. of a plasticizer to 100 pts.wt. of an aliphatic polyester resin melting at 55-120 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable wood aliphatic polyester resin composition. In detail, melt molding can be easily performed by extrusion molding, injection molding, blow molding, calendar molding, etc., and the molding material can be used in a wide range of fields such as gardening goods such as seedling pots and leisure goods such as golf tees. The present invention relates to a biodegradable wood-based aliphatic polyester resin composition that is degraded by microorganisms.

[0002]

2. Description of the Related Art Conventionally, polyethylene, polypropylene,
Plastics represented by polystyrene, vinyl chloride, polyester, polyamide and the like are widely used from necessities of daily life to industrial products. In recent years, from the standpoint of environmental protection such as garbage, the recycling of plastic has been called out, and in fields where recycling is not possible, the use of biodegradable plastic is strongly demanded by society.

[0003] Up to now, cost reduction and physical property improvement,
A method of adding wood flour to a biodegradable resin has been adopted for the purpose of reducing environmental burden. For example, JP-A-2000-129143
In the publication, a material in which wood powder or the like is blended with a biodegradable resin is described, and a composition composed of biodegradable resin / wood powder has attracted attention. However, in the prior art, in the production and molding of a compound containing wood flour, it is necessary to remove the water in the wood flour, which places a heavy burden on production and molding. If the drying step is omitted, water evaporates and foams, and pellets and molded products having a regular shape cannot be obtained. Furthermore, wood flour has a problem that the color tone changes remarkably when a temperature of 150 ° C. or more is applied.

[0004]

SUMMARY OF THE INVENTION The present invention solves the problems of the prior art as described above, and provides mechanical performance, biodegradability,
An object of the present invention is to provide a biodegradable resin composition which is excellent in molding workability and further provides a woody feeling with excellent design properties.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a specific lubricant and a plasticizer are added to a mixture of an aliphatic polyester resin and wood flour to dry the mixture. 130 ° C. or less, preferably 10 ° C.
It can be kneaded at a temperature of 0 ° C or less and can be used for all molding methods such as profile extrusion, injection molding, blow molding, etc., and foaming does not occur in molded products, and molded products with wood-like texture can be obtained. And completed the present invention.

That is, the present invention has a melting point of 55.degree.
A raw material characterized in that 30 to 200 parts by weight of an organic filler, 0.1 to 7 parts by weight of a lubricant and / or 1 to 50 parts by weight of a plasticizer are blended with 100 parts by weight of an aliphatic polyester resin at 0 ° C. It is a degradable wood aliphatic polyester resin composition. Here, the flexural modulus of a molded article obtained from the biodegradable woody aliphatic polyester resin composition of the present invention is as follows:
Preferably, the pressure is 1,500 MPa or more. Further, by adding an edible pigment and / or an inorganic colorant to the composition of the present invention, a colored biodegradable woody aliphatic polyester resin composition can be obtained. Further, the biodegradable wood aliphatic polyester resin composition of the present invention has a temperature of 130 ° C.
It can be used as a pellet compound by melt-kneading at the following temperature and pelletizing. Next, the present invention is characterized in that the biodegradable woody aliphatic polyester resin composition in the form of powder and / or pellets is molded at a molding temperature of 130 ° C. or less. The present invention relates to a method for processing a polyester resin composition. Here, a wood grain pattern or a marble pattern can also be given to a molded product by melt-molding the biodegradable woody aliphatic polyester resin composition of the present invention in the form of colored pellets of two or more colors.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the aliphatic polyester in the present invention, commercially available products can be used. For example, Bionole (trade name) sold by Showa Polymer Co., Ltd. may be mentioned. Resins, such as polycaprolactone, can be arbitrarily selected according to the use and characteristics. Industrially, those synthesized using an aliphatic dicarboxylic acid and an excess of diol as a starting material by a dehydration polycondensation reaction and a diol removal reaction are exemplified. As such an aliphatic polyester, polybutylene succinate and polybutylene succinate adipate are generally used, and various high molecular weight types are industrially produced.

Examples of the aliphatic polyester preferably used in the present invention include polybutylene succinate (a binary condensate of succinic acid and 1,4-butanediol) and polybutylene succinate adipate (succinic acid and adipic acid, And a ternary condensate of 1,4-butanediol)
Is mentioned. In addition, aliphatic diols and polyhydric alcohols such as 1,4-butanediol, ethylene glycol, propylene glycol, 1,6-hexanediol, and 1,4-hexamethylene dimethanol, and succinic acid, adipic acid, and sebacine An aliphatic polyester obtained by polycondensing a dicarboxylic acid such as an acid or an aliphatic polyhydric alcohol can also be used. In the above-mentioned aliphatic polyester, a functional group such as an isocyanate group or a urethane group is introduced into the structure for the purpose of improving the functionality within a range that does not impair biodegradability, or polylactic acid or an aliphatic polyester carbonate. It is also possible to introduce a copolymer of

[0009] The melting point of the aliphatic polyester used in the present invention is limited to the range of 55 ° C to 120 ° C. 55 ° C
If it is less than 1, the heat resistance of the molded article is low, and it is not possible to obtain a molded article having a desired heat distortion temperature.

Next, in the present invention, the organic filler is not particularly limited as long as it is an organic filler. For example, wood powder, rice husk powder, refined pulp, straw, paper,
Cotton, rayon, soup, cellulose and coconut powder, and further processed with at least one surface treatment agent selected from the group of silane coupling agents, titanium coupling agents and fatty acids (metal salts). Or an organic filler containing a small amount of a white inorganic pigment therein. The organic filler is an additive that gives the biodegradable woody aliphatic polyester resin composition of the present invention a woody feel.

The amount of the organic filler is 30 to 200 parts by weight based on 100 parts by weight of the aliphatic polyester resin.
Parts by weight. Considering the feeling of wood, cost merit, moldability, mechanical properties, and the like, 30 to 160 parts by weight is preferable. If it is less than 30 parts by weight, the desired woody texture and mechanical properties cannot be obtained, while if it exceeds 200 parts by weight,
Manufacture and molding workability of pellets become difficult.

Next, as the lubricant used in the present invention,
Those having a melting point of 120 ° C. or less are preferred. As a lubricant,
Among them, those having biodegradability are preferable, and polyethylene wax, oxidized polyethylene wax, fatty acid wax, glycol fatty acid ester wax, glycerin fatty acid ester wax, fatty acid ester wax,
Citrate ester wax, montanic ester wax, partially saponified montanic ester wax, dipentaerythritol ester wax and the like.

As the plasticizer, any plasticizer can be used as long as it is used as a plasticizer for a synthetic resin.
For applications intended for biodegradation, it is preferable to use a plasticizer which is easily biodegradable and has compatibility with the aliphatic polyester resin. Particularly preferred plasticizers include glycol fatty acid esters, glycerin fatty acid esters, fatty acid esters, citrate esters, and the like.

In the present invention, one or more of the above-mentioned lubricants and / or one or more of the above-mentioned plasticizers are added, and 100 parts by weight of the above-mentioned aliphatic polyester resin is used. 0.1 to 7 parts by weight, a plasticizer is preferably 1 to 50 parts by weight, and considering moldability and mechanical properties, a lubricant is 0.3 to 4 parts by weight, and a plasticizer is 5 to 30 parts by weight. More preferred. When the amount of the lubricant or the plasticizer is less than the predetermined weight, 13
Pellet production and molding at 0 ° C. or lower are difficult, and the effects of the present invention cannot be obtained. On the other hand, when the amount exceeds the predetermined weight part, not only the problem of bloom and bleeding occurs, but also the moldability and mechanical properties are deteriorated.

As the colorant used in the resin composition of the present invention, any colorant can be used as long as it is used as a colorant for a synthetic resin. Those having low toxicity when only the colorant remains are preferred. As particularly preferred coloring agents, food colors and inorganic pigments are added as coloring agents. As food colors, food red No. 2, No. 3, No. 40, food yellow No. 4, No. 5
No. 3, Food Green No. 3, Food Blue No. 1, No. 2, etc., aluminum lake pigments and the like can be used. Further, as the inorganic pigment, titanium oxide, red iron oxide, ultramarine blue and the like can be used. One of these colorants may be used, but two or more colors may be used in combination. The amount of the coloring agent used is based on 100 parts by weight of the aliphatic polyester resin.
Preferably 0.1 to 50 parts by weight, more preferably 0.1 to 50 parts by weight.
It is about 5 to 20 parts by weight.

To the resin composition of the present invention, an organic or inorganic filler including other polymer materials can be arbitrarily added to the composition of the present invention as long as the effects of the present invention are not impaired. is there. Since the composition of the present invention is particularly characterized by biodegradability, it is necessary to use a polymer material and an organic additive which are optionally added to those having biodegradable properties or harmless to nature. Is preferred. For example, as an inorganic filler, calcium carbonate, talc, derived from natural ore,
In addition to mica, calcium silicate and silica, it is possible to use special fillers such as barium sulfate and metal powder.

The composition of the present invention can be melt-kneaded at a temperature of preferably 130 ° C. or lower, more preferably 80 to 125 ° C., particularly preferably 90 to 120 ° C. It can be used as a pellet compound. When various fillers are mixed with a resin, a pellet compound is particularly desirable. This is because the various components can be uniformly predispersed by pellet processing, and molding stability can be obtained. Further, the composition of the present invention is not limited to a pellet compound, and a powdery mixture obtained by blending the blend is also preferably 130 ° C or lower, more preferably 80 to 125 ° C, particularly preferably 90 to 120 ° C.
It is also possible to carry out molding at a molding temperature of ° C.

When the composition of the present invention is molded, it is melted in each molding machine and molded by various molding machines such as extrusion molding including profile extrusion, injection molding, blow molding, calender molding, vacuum molding and embossing molding. It is possible. Further, a molded product expressing a wood grain pattern or a marble pattern can be obtained by blending, mixing and molding a colored composition in the form of two or more pellets.

As a mixer used in the processing of the pellet compound, a blender for the purpose of preliminary dispersion, distribution, and diffusion mixing is used as the preliminary mixer.
Typical examples of the blender include a ribbon blender, a Henschel mixer (super mixer), a tumble mixer (tumbler mixer, drum tumbler mixer), and an air blender. These premixers are selected according to the form and diffusion level of the plasticizer and auxiliary materials to be filled. In the prior art, it is necessary to remove water contained in the composition, mainly in the organic filler, before or after the mixing or during the mixing. In the present invention, there is no need for this, and workability is greatly improved.

The melt kneading machine is generally a single-screw or twin-screw extruder, a Banbury type, a roll type, or the like. These can also be selected according to the form, purpose, and productivity of the composition, and melt-kneaded to produce a pellet-shaped raw material (pellet compound). Further, as a method of forming the melt-kneaded material into a pellet shape, the molten resin composition is extruded from a die into a string,
There are a strand method in which pellets are produced by a strand cutter after water cooling and / or air cooling, and a hot cut method in which pellets are produced by a die cutter while extruding a molten resin composition from a die in a string shape.
For the present invention, any method can be adopted.
In particular, it is an excellent effect that a hot cut method with good workability is possible.

The composition of the present invention can be used for any molding method. As a typical molding machine such as injection molding and extrusion molding, a molding machine having a generally used general specification can be employed.
In the prior art, a pellet compound or a powdery compound requires a drying step before molding in order to absorb moisture, but in the present invention, there is no need for this, and workability here is greatly improved. To be improved. For example, in the case of injection molding, a general injection molding machine can be used. In general, the use of the compound in the form of pellets results in good finished products and stable physical performance. Thus, the molding method of the composition of the present invention can be selected according to the use.

The flexural modulus of the molded article comprising the biodegradable woody aliphatic polyester resin composition of the present invention obtained as described above is preferably 1,500 MPa or more, more preferably 1,600 to 5,000 MPa. It is. This flexural modulus, for example, the amount of organic fillers such as wood flour, depending on the type of plasticizer and aliphatic polyester resin,
It can be easily adjusted.

[0023]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, parts and%
Are by weight unless otherwise indicated.

<Sample> As the aliphatic polyester resin,
Bionore # 3020 and # 30 manufactured by Showa High Polymer Co., Ltd.
01 (both melting points 95 ° C.). As an organic filler, wood powder 120M (average particle size = 75) manufactured by Obayashi Kogyo
μm). As the cellulose powder, W-100 manufactured by Nippon Paper Industries was used. As a lubricant, polyethylene wax LBT-77 (melting point 75 ° C.) manufactured by Sakai Chemical Co., Ltd., and stearic acid monoglyceride S-100 (melting point 6) manufactured by RIKEN Vitamin.
5 ° C.), and partially saponified montanic acid ester HW-OP (melting point: 75 ° C.) manufactured by Clariant Japan. Monocapryl diacetyl glyceride (GA
O), monoacetylglyceride (GMA), triacetin (GTA), acetyltriethyl citrate (ATE
C) was used.

<Sample preparation method> Using a tumbler mixer as a premixer, a resin, a wood powder, a lubricant or a plasticizer were mixed at a predetermined ratio and a stirring operation was performed. As a kneader, using a screw diameter 65 mm different direction biaxial extruder,
Melt kneading was performed at a cylinder set temperature of 50 to 130 ° C. While extruding the molten resin composition from a die in a string shape, a pellet compound was prepared by a hot cut method of forming a pellet by a die cutter.

<Pellet Manufacturability> The melt uniformity of the composition during the melt-kneading operation using the kneader, the magnitude of the load of the motor for operating the kneader and the discharge amount, and the appearance of the pellets were evaluated. The evaluation criteria are as follows. Good meltability : The state where the melt-kneading of the composition is uniform Normal: The kneaded composition has a slight melting defect, but is in a state in which molding can be performed Poor: The composition is unevenly melted or unmelted and cannot be molded Good motor load and discharge rate : The motor load of the twin screw extruder is stable at less than 60A,
40 kg / h or more ejection failure state stably obtained: the discharge amount is less than 40 kg / h, productivity is bad not: 2 motor load of screw extruder 60A above, state pellet is impossible production Good appearance : Pellet shape is uniform and foaming is not seen. Poor: Pellet shape is uneven or foaming phenomenon occurs.

<Injection molding processability> In injection molding, an injection molding machine with a mold clamping pressure of 80 t was used, and a cylinder set temperature of 60 was used.
The molding was performed at a mold set temperature of 40 ° C. Using a film gate type plate (width 6 × length 6 × thickness 0.3 cm), workability at the time of molding and appearance of the obtained molded product were evaluated. The evaluation criteria are shown below. Good workability : Injection pressure is less than 80% setting with respect to maximum pressure Poor: Injection pressure has more than 80% setting, load on screw is high, metering is unstable, or plasticizer from composition When the lubricant separates. Good appearance of molded article : When no abnormalities are found on the surface of the molded article visually. Poor: Bubbling phenomenon is visually observed, the surface of the molded product is colored, flash marks, gloss unevenness, and bumps are present.

<Extrusion processability> Extrusion is 20 mm
Using a single screw extruder, set cylinder temperature 60-100
℃, using a tape die, screw rotation 30rpm
The extruder was evaluated for workability and appearance of a molded product. The evaluation criteria are shown below. Good workability : When the extrusion load (torque) is lower than 5 kg / cm ² Poor: When the extrusion load (torque) is 5 kg / cm ² or more Good appearance of the molded article: Visually, especially abnormalities are observed on the molded article surface If not: Poor: Visually visible foaming of molded product, uneven melting or melt fracture on surface

<Evaluation of bleed and bloom-out> Width 6
X Length 6 x Thickness 0.3cm Using a film gate type plate, leave it at 40 ° C and 90% RH for 1 week, and check whether there is a bloom out of lubricant and a bleed out of plasticizer on the plate surface. Was performed visually.

<Physical property test>
The temperature was adjusted at 50 ° C. and 50% RH for 24 hours, and the measurement was performed according to the following standards. The bending test was performed using a 1/4 inch test piece in accordance with ASTM D792.

Examples 1 to 14 Wood powder 120M and cellulose powder W-100 were mixed with 50, 75, 100, and 150 parts of 100 parts of Bionole # 3020 and # 3001, respectively, and a lubricant, a plasticizer, and a colorant were added. And mixed using a tumbler mixer. The compounding weight parts are shown in Tables 1 to 3. As a melt kneader, a different direction twin screw extruder with a screw diameter of 65 mm was used, the cylinder temperature was set to 100 ° C., melt kneading was performed, and a pellet compound was produced by a hot cut method. In each of the examples, the kneading workability was good, and no bleeding or blooming out of the molded product was observed. The injection molding processability was good for Examples 1 to 8, and the extrusion processability was good for Examples 9 to 13.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

Example 15 The light brown and dark brown pellets obtained in Examples 11 and 12 were mixed at a weight ratio of 95: 5, and the cylinder was set at a temperature of 60 to 100 ° C. using a 20 mm single screw extruder. When extrusion molding was performed using a tape-shaped die at a screw rotation of 30 rpm, a grain pattern was expressed in the molded product, and a molded product having a high design quality and a woody feel was obtained.

Example 16 (Powder molding) The compound of Example 11 was directly extruded using a 20 mm single screw extruder at a cylinder set temperature of 60 to 100 ° C. using a tape-shaped die at a screw rotation of 30 rpm. As a result, the same good evaluation result as that of Example 6 in which pelletization was performed was obtained.

Example 17 100 parts of wood flour 120M was mixed with 100 parts of Bionole # 3020, 1 part of lubricant HW-OP was added and mixed using a tumbler mixer. As a melt kneader,
Using a twin screw extruder with a screw diameter of 65 mm, the cylinder temperature was set to 140 ° C and melt kneading was performed. The molten resin was extruded into a string, but there was a foaming phenomenon, but pellet production was possible. Met.

Example 18 Using the pellets obtained in Example 1, a mold clamping pressure of 80
Using an injection molding machine of t, molding was performed at a cylinder set temperature of 140 ° C. and a mold set temperature of 40 ° C. The molded product had a foaming phenomenon, but a molded product was obtained.

Example 19 The pellets obtained in Example 11 were extruded using a 20 mm single screw extruder at a cylinder set temperature of 140 ° C., using a tape-shaped die at a screw rotation of 30 rpm. Although the product had a foaming phenomenon, a molded product was formed.

Comparative Examples 1 to 6 Wood flour 120M, Bionole # 3020 and # 300
1. Other additives were added and mixed using a tumbler mixer, pellets were prepared in the same manner as in Example 1, and the kneading workability, molding workability, bleed, bloom-out properties, and physical properties were evaluated. Table 4 shows the compounding parts by weight, kneading workability, molding workability, bleed and bloom-out evaluation, and physical properties. In Comparative Examples 1 and 4, the flexural modulus was low, and physical properties close to wood could not be obtained. Comparative Example 2, Comparative Example 3, Comparative Example 5,
In Comparative Example 6, a load was applied at the time of melt-kneading and pellets could not be formed.

[0041]

[Table 4]

Comparative Example 7 100 parts of wood powder 120M was mixed with 100 parts of polylactic acid (melting point 170 ° C.), 1 part of a lubricant HW-OP was added, and the mixture was mixed using a tumbler mixer. As the melt kneader, using a different direction twin screw extruder with a screw diameter of 65 mm,
The temperature of the cylinder was set to 170 ° C., and the mixture was melt-kneaded. The molten resin was extruded in a string shape, but a foaming phenomenon occurred and pellet production was impossible.

Comparative Example 8 100 parts of wood powder 120M was mixed with 100 parts of polylactic acid (melting point 170 ° C.), 1 part of a lubricant HW-OP was added and mixed using a tumbler mixer. As the melt kneader, using a different direction twin screw extruder with a screw diameter of 65 mm,
The cylinder temperature was set to 130 ° C. and melt kneading was attempted, but the resin did not melt and pellet production was impossible.

[0044]

According to the present invention, there is no need for a drying step of the blended composition, hot cutting is possible at the time of pellet production, and production can be carried out at a low temperature of 130 ° C. or less. Are better. In addition, the molding temperature is set to 130
The composition is a composition which can be performed at a temperature of not more than ℃, the foaming phenomenon does not appear in the obtained molded article, a high woody feeling, a biodegradable wood aliphatic polyester capable of producing a highly designed molded article A resin composition and a method for producing the same are provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/10 C08K 5/10 C08L 97/00 C08L 97/00 // B29K 67:00 B29K 67:00 F Terms (reference) 4F070 AA02 AA47 AA66 AC15 AC43 AC94 AE02 AE04 AE09 FA03 FA17 FB06 FC05 4F201 AA24 AB07 AB11 AB12 AD06 AF08 AF09 AH01 BA02 BC01 BC10 BC19 BC37 BK13 BK26 BL08 BL43 4J002 AB012 AE033 AH002B03 EB023 FD173 GA00 GC00

Claims (6)

[Claims] 1. An organic-based filler 30 to 100 parts by weight of an aliphatic polyester resin having a melting point of 55 ° C. to 120 ° C.
A biodegradable wood-based aliphatic polyester resin composition comprising 200 parts by weight, 0.1 to 7 parts by weight of a lubricant and / or 1 to 50 parts by weight of a plasticizer. 2. The molded product has a flexural modulus of 1,500 MPa.
The biodegradable woody aliphatic polyester resin composition according to claim 1, which is the above. 3. The biodegradable wood-aliphatic polyester resin composition according to claim 1, further comprising an edible dye and / or an inorganic colorant. 4. The biodegradable wood-aliphatic polyester resin composition according to claim 1, which is melt-kneaded at 130 ° C. or lower and pelletized. 5. A powdery and / or pelletized biodegradable wood-aliphatic polyester resin composition, comprising:
The molding method of the biodegradable wood-aliphatic polyester resin composition according to any one of claims 1 to 4, wherein the molding is performed at a molding temperature of not more than ° C. 6. A wood grain pattern or a marble pattern is applied to a molded product by melt-molding a colored pellet-shaped composition of two or more colors.
A method for forming and processing the biodegradable wood-based aliphatic polyester resin composition according to any one of the preceding claims.