JPH06500819A - Film containing polyhydroxy acid and compatibilizer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] name of invention Background of the invention of film containing polyhydroxy acid and compatibilizer The present invention consists of a polyhydroxy acid (PHA), a compatibilizer, and a and its preparation. The invention also relates to such compositions. and other polymers.

High molecular weight substances of hydroxy acids and 2-hydroxy acids, especially glycolic acid and The cyclic dimer product of lactic acid esterification is likely to be degradable (not known). Ru. These materials degrade substantially and easily into harmless by-products under natural environmental conditions. can be used in single-use packaging or in waste treatment facilities. highly useful Films (many known polymers such as polyolefins, polycarbonates, Constructed from nylon and cellophane. Polyolefin film itself does not degrade in the environment, posing a waste disposal problem. Polyole Fin film is made by incorporating starch into the polymer, which is why it is made of polyolefin. It has deteriorated and disintegrated to the level of flakes. These polyolefin/starch blends (used for many uses such as food waste bags, but these are not transparent and therefore However, its use is limited.

5chneider in U.S. Patent No. 2.703.316. However, the blending with compatibilizers and other polymers is not disclosed. Not shown. Encyc-1opedia of Polymer 5cie nce and Engineering, Mark Sonoike (1987) Although it discloses the use of blends of polymers and compatibilizers, any polyhydroxy Acids are also not disclosed, nor is the long-standing use of polyhydroxy acids and their degradability known. Despite this, there is no discussion of degradability.

A film that can have physical properties that can be adapted to specific uses. optically clear and tough heat for commercially useful packaging and other applications. A highly degradable material that can be processed economically and with high yields into sealable films. According to the present invention, it is desired to provide a composition containing a polyhydroxy acid (PHA). ) and a compatibilizer. These compositions contain both polymers. A fiber that possesses the properties, especially the transparency and degradability of polyhydroxy acids, to a considerable degree. It is useful for blending with other thermoplastic polymers to provide lume.

Articles made in blends with these ingredients are further provided and made according to the invention. High degradability of the film is achieved through the use of polyhydroxy acids. Specification The "polyhydroxy acids" used in this book are at least one selected from the following: means a polymer containing hydroxy acid units.

(i) [0(CR’R’)nco)p(u)(COR’R″C00CR ’　R’C0)Q(ffl　)　(COR’R’CR’R’OCR’R’C0) r(tv) (COR' R'CR' R'ZCR' R'CR' R'C0 )s(v) (t) to (tv) copolymers with non-hydroxy acid comonomers Here, n is 2.4 or 5; p, q, r and S are integers, and the sum of these is about 50 ~5.000; R' and R' each independently represent hydrogen, 1 to 12 carbon atoms; hydrocarbyl or substituted hydrocarbyl containing: Z is oxygen, sulfur, NH or P [It is l. The polyhydroxy acid is contained in an amount of 5 to 90% by weight.

The compatibilizer is present in an amount of 5 to about 75 weight percent of the polyhydroxy/compatibilizer composition. Contained in an amount of ” As discussed in two series of Mark et al. When included in a blend of substantially immiscible polymers, the oxidizing agent improves the overall polymer composition. The composition provides intimate blending of the polymers with no signs of clumping. phase Solubilizers produce compatible blends that are homogeneous at the macroscopic level; Blends that are quality are not compatible. In its broadest concept, a compatibilizer is a pond polymer The specific polymerization process must contain chemical components that are compatible with each of the Specific to body blends. In the present invention, all compatibilizers are polyhydroxy It does not have the chemical or physical ability to be compatible with acids and other specific polymeric components. Must be. Therefore, whether other polymer components are blended or The selection of an effective compatibilizer depends on whether it can be compatibilized with the hydroxyacid. This is done based on the known chemical and physical properties of the other polymeric components of the polymer. If one If more than one species of polymer is present in the other polymer components, more than one compatibilizer may be required to obtain a homogeneous blend. polyhydroxy acid and Table I lists examples of compatibilizers that when mixed result in compatible compositions.

The amount of compatibilizer required depends on the relative amount of polyhydroxy acid and the total polyhydroxy acid. It will vary depending on the acid/compatibilizer/polymer blend ratio. in a suitable composition. Polymers other than those of formulas (f) to (v) have the last three or more components. present in an amount up to about 90% by weight of the product.

The polyhydroxy acid/compatibilizer composition of the present invention comprises a polyhydroxy acid and a specific compatibilizer composition. Dry mixing of polyhydroxy acid and a compatibilizer that is compatible with the other three component polymers or prepared by melt blending.

The film of the present invention is a homogeneous composition that is a solution or a blend of closely homogeneous small particles. Polyhydroxy acid/compatibilizer/polymer assembly under sufficient mechanical agitation to obtain prepared by melt processing the composition. This film product is then dissolved Molded by conventional techniques such as casting, extrusion or tube blow molding It is usually made into a film with a uniform thickness of 0.01 to 2 mm.

Examples of suitable non-hydroxy acid comonomers in formula (V) include lactide or lactic acid and Those capable of condensation polymerization, namely ε-caprolactone, β-propiolactone: α -dimethyl-β-propiolactone: such as glycolide and dodecanolactone Included are lactones as well as lactams. For a more complete list, please visit the U.S. See column 9, line 27 of patent no. 4,800.219.

The compositions of the present invention containing polyhydroxy acids have a viscosity sufficient to obtain a satisfactory viscosity. forming a supportive film from the polymer melt with at least a high average molecular weight; It has the strength of about 2.000 to about 600.00 for polyhydroxy acid A weight average molecular weight of 0 can be used. Preferably, the polyhydroxy acid is Contains more than half of the polymer content of the final film product containing a compatibilizer polymer of In this case, a polyhydroxy acid molecular weight of about 20.000 to about 450.000 is used. polyhydroxy acid: and the polyhydroxy acid contains less than half of the polymer content of the final film product. polyhydroxy acid molecular weights of 4,000 to 20,000 are used when Ru.

The term "degradable" as used herein with respect to polyhydroxy acids refers to degradable materials. The polyhydroxy acid portion of the material is biodegradable and, more importantly, resistant to hydrolysis. This means that it is degradable. The rate of decomposition is consistent with the intended use, i.e. Although the product does not decompose significantly during normal storage and use, it , which decomposes after an appropriate amount of time.

Hydrolytic degradation of polymers to suit film usage and processing requirements Can be easily adjusted.

It mainly depends on the nature of the groups in the molecular chain.

(as is known, moisture, pi, temperature, ionic strength, solar radiation, enzymes, Certain conditions, such as coalescence crystallinity and hydrophilicity of the polymer, can influence the degradation of the polymer. affect

The degradation rate of polyhydroxy polymers is excessive for many typical packaging applications. (i.e., the cost of packaging film from production to product application) During the expected shelf life of the packaging, including the shelf life, this packaging film will (will deteriorate over time). The reduction in tensile strength of the film caused by aging is shrinkage. During processing by the packaging machine, the film ruptures and is not accepted for packaging applications in the market. Become something you can't be. In addition, the amount of shrinkage or resistance of the film can be adjusted depending on the specific application. It may become inappropriate. These defects cause the polymer composition to have non-polyhydrocarbons. This can be controlled by including an xylene polymer. non-polyhydroxy Polymers do not blur or distort in graphic arts, etc. A polymer that creates a transparent film.

Suitable non-polyhydroxy polymers for the present invention include polyolefins, polyethers, polyester, polyamide, polyvinyl chloride, polycarbonate, polyester Ruphon, copolyether ester, polyurethane, ethylene/vinyl alcohol Copolymer, copolyamide ether ester, ethylene/vinyl ester copolymer and terpolymers, ethylene/acrylic acid copolymers and terpolymers and their Metal salts, ethylene-carbon oxide copolymers and copolyetherimide esters are included. Included.

[Hazy] products, which are outside the scope of the present invention, are due to insufficient compatibilization, Extrusion of low molecular weight plasticizer onto the film surface, high crystalline content of the starting polymer and its Transparency has been undermined by others.

The term "ambient temperature" refers to the highest temperature to which the film product is exposed during use or storage. means. This temperature is usually room temperature (20°C) or lower if refrigerated. The temperature is up to 40°C or higher if stored in a warehouse.

Suitable polyhydroxy acids of the present invention contain from 50 to 99 mole percent of hydroxide. composed of roxy acid units (i) (wherein R' is hydrogen and R' is a methyl group); a polyhydroxy acid component having 80 to 97 mol % of asymmetric carbon atoms in the R-configuration; and 3-20 mol% S-configuration or 80-97 mol% S-configuration and 3-20 mol % R-configuration, and 1 to 45 mol% of this polyhydroxy acid is , the total R- or S-configuration in the main component and product components exceeds 97 mol% of asymmetric carbon atoms. Hydroxy acid units (i) or (if) with asymmetric carbon content such that or a suitable non-hydroxy acid comonomer. It is a polyhydroxy acid, which is a small component of These suitable polyhydroxy acids will be explained by way of example. For example, suitable polyhydroxy acids contain asymmetric carbon atoms. The main component consists of 67 mol% of hydroxy acid units (i) of which 90% are in the S-configuration. May be contained. In this example, the minor component polyhydroxy acid is 35 mol%. and with hydroxy acid units (il) or suitable hydroxy acid comonomers May be fully configured. In this same preferred example, a component of the S-configuration is Some of the symmetrical carbon atoms are added to the S-atoms of the polyhydroxy acid component, When the asymmetric carbon atom does not increase the above-mentioned total 97 mol% S-atom content The product of polyhydroxy acid unless it cannot be larger than a part of the child. may be an additional hydroxy acid unit (i).

In a further preferred embodiment of the invention, R- and S-asymmetric carbons in polyhydroxy acids The range of elementary atoms is 85-96 mol%.

To determine relative R- and S-content, best processability and ultimate product properties are required. In order to obtain polyhydroxy acids with melting points close to those of other polymers, must be taken into consideration. Therefore, some compositions have very high R-contents. It may be that a large amount is not necessarily desired.

The terms "R-" and "S-" are standards for identifying stereoisomeric configurations for asymmetric carbon atoms. This is due to nomenclature. The percentages of R- and S-carbons indicated herein are Concerning only the portion of asymmetric carbon atoms in the hydroxy acid polymer chain, polymerization It does not involve all carbon atoms in the body chain.

An asymmetric carbon atom is one that has less than four different substituents attached to it.

Polymers with more equal R- and S-carbon atom moieties are promoted by hydrolysis. Adjacent layers of the film often stick to each other and film formation Suitable compositions are selected because they produce films that tend to disintegrate during one culm. It has a narrow range of asymmetric carbon atoms.

Also, films made outside these ranges may be cloudy and/or brittle. obtain. For example, a polymer film having a portion above the S-carbon atom range is After processing, for example during film production, it becomes substantially crystalline. Crystallinity film forming performance and the optical clarity of films formed from crystalline polymers. It is harmful.

A method to reduce the negative effects of highly crystalline polymers on film properties is to By dispersing a polymer or a low molecular weight ribomer in a polymer matrix. This is to plasticize the polymer. Plasticization of the polyhydroxy acid of the present invention The agent is monomeric hydroxy acid, monomeric hydroxy acid lactide, monomeric hydro lactyl lactate uncyclized dimer of oxyacid and monomeric lactyl hydroxyacid with molecular weight up to about 450. It is an oligomer of droxy acid.

However, large amounts of plasticizer result in films of uneven thickness. drum When a film is made by casting on top, excess plasticizer separates from the film. , it may stick to the drum and contaminate the drum, and it may also cause the film to stick to the drum. It's possible. Therefore, it is necessary to use polymers containing a minimum amount of plasticizer. understood. The amount of plasticizer required to obtain useful films of this invention ranges from about 0.10 to About 8 weight percent, preferably about 0.2 to 6 weight percent. very A highly preferred composition range is about 0.2 to 0.4 weight percent plasticizer. child The amount of these plasticizers used is relative to the polyhydroxy acids in the feedstock to the film manufacturing process. Based on the concentration of plasticizer, the concentration of plasticizer in the film made from the composition of the present invention It is not necessarily based on Plasticizer content is determined by Kohn, Van denB erg, Van de Ridder and Feyen; J, App Lied PolyverScience, Vol 29. p, 4265~ 4277 (1984). be able to.

When it is necessary to reduce the plasticizer concentration in a plasticizer-rich composition, a separation step and A devolatilizing extruder can be used either before or during film extrusion. can.

Example The compatibilizer used in this example is as follows: TRX-1ot HF@( (manufactured by DuPont), maleic anhydride is added to ethylene-propylene copolymer. Rafted: ELvax@360 (manufactured by Du Pant), ethylene and Copolymer with vinyl acetate; Fusabond OD-100 and Fusabon dOD-111 (manufactured by DuPant), maleic anhydride added to polyethylene Nucrel O0407 (manufactured by DuPont) and Nuc reLO0903 (manufactured by Du Pant), copolymer of ethylene doacrylate . SurylnOIonomer #1650 and #1601 (DuPont) ) is the salt of NucreLO. EMA@2205 and 2207 (Chevr on) is a copolymer of ethylene and methyl acrylic acid. These compatibilizers are All have both hydrophilic and hydrophobic end groups.

1667g crystalline glycolic acid, 1894iy R-lactic acid and 3iy stannous octoate ．． Heat 3g of the mixture to add 50% polylactic acid, 150% polyglycolic acid (PLA /PG^) copolymer was prepared.

The reaction was carried out under atmospheric pressure and heating from room temperature to 136°C.

The pressure was then reduced to 100°C while heating to 190°C over 3 hours. Next 2 The mixture was heated for an additional 5 hours at 190° C. under 1 vacuum.

50150 copolymer with an average molecular weight of 6000 and a softening point of about 120°C was generated.

Next, low density polyethylene (LDPE) with a melt index of 2.0, E Using xxon #3060 and the compatibilizer listed in Table I, blend as shown in Table ■ was prepared. Add the above 50150 copolymer, LDPE and compatibilizer to Banbury. These three components are mixed in a mixer above their melting points and the particles having an average diameter of 174 inches are formed. It was crushed into pieces. The particles were dried in an oven.

Blend particles were fed into a screw feeder with a 1 inch diameter mouthpiece.

The temperature of the heating/melting zone was maintained at 175-225°C. Supply screw is 32r I drove at pm.

The film is then extruded to a thickness typically between 2 and 4 mils (0.05 to 0.1 mm). Blow molded.

Table 1 1 100 0 0 control 2 95 5 0 Low quality film 3 35 5 TRX@-1ot HF, 10% good quality film 4 80 1 0 Fusabond D-111, 10% high quality film 5 90 5 Fu sabondOD-111,5% High quality film 6 60 20 Fusabo ndOD-111, 20% acceptable before exposing these films to hydrolysis conditions In order to confirm the decomposition of the film by the subsequent tensile strength at break, and 5 were first tested and then heated in distilled water at 70° C. for 28 days. Table ■ shows water treatment The results of these tensile tests before and after are shown in lb/in” (psi). There is. MD indicates the extrusion direction, and TD indicates the lateral direction or circumferential direction.

The tensile strength (fracture) values of Examples 4 and 5 are compared to Example 1 (PE 100%). It exhibits high blow molding strength and relatively low strength (decomposition) after water treatment. It shows.

A similar film was prepared without blow molding, by directly casting the film. child The films had similar strength, clarity and degradability.

Example 7 50150% PL^/PGA copolymer lO%, E1vax036010% and L Commercial equipment from a blend containing 80% DPE (Exxon 3060) Several types of films were blow-molded to a thickness of 0.04 to 0.05 s+* using the following.

These films according to the invention are transparent, flexible and made of 100% LDPE control. It had elongation at break and tensile strength comparable to rolls. Biological digestion plant accelerated testing of these films by simulating exposure to urban sewage I did it. After 5 days of exposure, a biological oxygen demand (BO[l) of 300 ppm Obtained. After 20 days of exposure, the BOD further increased to 1400 ppl. This frame The film is completely destroyed by biological degradation of PLA/PG^.

■Comparison film with 00% LDPE has inferior strength and elongation properties, and is caused by sewage Similar to Example 1, PLA with an intrinsic viscosity of 1.1 did not decompose in the simulation test. Blend with Fusabond OD-111 in a Banbury mixer at a ratio of 1=2. I ran it. The resulting blend was ground into granules with an average diameter of 1/4 inch. A blow-molded film was made as in 1. The resulting film is highly degradable. Ivy.

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Claims (12)

[Claims] 1. (I)(i)[0(CR'R'')nCO]p(ii)(COR'R''C 00CR'R''CO)q(iii)(COR'R''CR'R''OCR'R ''CO) r(iv) (COR'R''CR'R''ZCR'R''CR'R' 'CO)s(v) Copolymer of (i) to (iv) and non-hydroxy acid comonomer (In the above formula, n is 2, 4 or 5; p, q, r and s are integers, and the sum of these is approximately 350 to 5,000; R' and R'' are each independently hydrogen, 1 to 12 Hydrocarbyl having carbon atoms or substituted hydrogen having 1 to 12 carbon atoms Drocarbyl; Z is selected from the group consisting of oxygen, sulfur, NR' or PR' 5-95% of polyhydroxy acids containing at least one unit; and (II) compatible curing agent 5 to 75% A composition consisting of 2. Another thermoplastic compatible with the combination of components (I) and (II) 2. The composition of claim 1, comprising up to 90% of a polyvalent polymer. 3. The thermoplastic polymer is selected from the group consisting of polyethylene and polypropylene. 3. The composition of claim 2. 4. Polyhydroxy acids (1) and 4 in an amount of 30-60% relative to the weight of the total composition 2. Composition according to claim 1, containing compatibilizer (II) in an amount of 0 to 70%. 5. The polyhydroxy acid is polyglycolic acid, polylactic acid, or a copolymer thereof. The composition of claim 1 selected from the group consisting of. 6. The compatibilizer is an ethylene/maleic anhydride graft polymer and an ethylene/maleic anhydride graft polymer. The composition of claim 1 selected from ethylene oxide copolymers. 7. A film containing the composition of claim 2. 8. 8. The film of claim 7, which is transparent. 9. Based on the film, 5 to 15% by weight of polyhydroxy acid (I); compatibilizer (I) 8. The film of claim 7, consisting of 5-20% I) and 60-90% thermoplastic polymer. . 10. intimately blending the dry ingredients of claim 2; heating to dissolve the blended ingredients; Melting: Forming a film from the melt and solidifying the film by cooling. A method for producing a film, comprising: 11. 11. The method of claim 10, wherein the film is formed by extrusion. 12. 11. The method of claim 10, wherein the extruded film is blow molded.