Poly-coated paper composites

Preconditions for the invention

The present invention relates to composites of polymer coated paper and thermoplastic resin.

Polymer coated paper (polymer coated paper) is used in a variety of applications. For example, polymer-coated paper is made into a wide variety of food packaging, including disposable juice packs and boxes for frozen foods.

Resins are also used in a variety of applications such as food packaging. Food packaging made of polymer-coated paper or resin is usually used once and then discarded. As a result, the amount of waste polymer-coated paper and resin used is constantly increasing.

The essence of the invention

In general terms, the present invention describes composites of textured polymer-coated paper and resin.

The present invention relates to a composite comprising at least 2%, and more preferably about 5% by weight, of a texturized polymer coated paper and resin such as a thermoplastic resin. Such a composite may also contain cellulose or lignocellulosic fibers.

The present invention also relates to a composite comprising polyethylene and at least 50% by weight of the composite textured polymer coated paper.

The present invention further provides polymer coated paper and resin composites having a tensile strength of at least 3000 psi (536.22 kg / cm) or a tensile strength of at least 3000 psi (536.22 kg / cm). cm).

Furthermore, the present invention describes a method of making a composite. This method of production involves cutting the polymer coated paper to form a textured polymer coated paper and subsequently bonding the textured polymer coated paper to the resin. The most suitable method is to cut the polymer-coated paper with a rotating knife. The present invention also relates to a process for making a composite comprising cutting a polymer coated paper and bonding the polymer coated paper to a resin.

As used herein, the term "textured polymer-coated paper" means that the paper is cut until the inner fibers are substantially exposed. Not less than 50%, and even more preferably not less than 70% of said fibers, as well as a length / diameter (L / D) ratio of said outer polymeric fibers of at least 10, more preferably not. less than 25 or 50. An example of textured polymer coated paper is shown in FIG. 1.

The composites of the present invention are strong, lightweight and inexpensive. It is easy to obtain raw materials for the production of these composites, for example, it can be used in resin or polymer coated paper packages.

Polymer-coated paper can be difficult to recycle, since for many applications paper and polymer must be separated from one another. The present invention utilizes both paper and polymeric parts, so there is no need to separate them from one another. As a result, the present invention facilitates the recycling of unnecessary used packaging while providing useful materials.

Other features and advantages of the present invention will be apparent from the description of the most preferred embodiments thereof, and from the claims.

Brief description of the drawing

Fig. 1 shows a photograph of a 50x magnified sample of one textured polymer coated paper.

Description of the preferred embodiment

The preferred composite consists of textured polymer coated paper and resin.

Textured polymer coated paper gives the composite strength. The textured paper composition may comprise from about 30% to about 90%, more preferably from about 50% to about 70% by weight of the composite. Examples of polymer-coated paper include polymer-paper-based materials and paper-polymer-aluminum-layer materials. Preferably, polymer coated paper has layers of polymer and paper.

Polymer coated paper is available in a variety of forms. For example, continuous sheets of raw polymer coated paper are sold by International Paper, New York. Alternatively, polymer-coated paper cuttings are available from International Paper or from other paper manufacturers. Used polymer coated paper in the form of discarded food and beverage packaging can be obtained from a variety of locations, including landfills. Used polymer coated paper can also be purchased from brokers of this material. If the composite uses used polymer-coated paper, it must be thoroughly washed beforehand. Polymer-coated paper cuts are best suited because they are cheaper than continuous sheets.

The resins envelop the textured polymer-coated paper and help control the appearance of the composite. The resins also transfer external loads to the polymer-coated paper and protect the polymer-coated paper from environmental impact and structural damage. Most preferably, the composition contains from about 20% to about 60% resins, more preferably from about 30% to about 50% by weight of the composite.

Examples of resins include polyethylene (including, for example, low density polyethylene and high density polyethylene), polypropylene, polystyrene, polycarbonate, polybutylene, thermoplastic polyethers, polyesters, thermoplastic polyurethane, polyvinyl chloride, nylon, and other resins. It is desirable to have a low yield strength. Preferred resins include polyethylene and polypropylene having a flow rate of less than 3 g / 10 min, and even better when less than 1 g / 10 min.

These resins can be purchased as raw materials or obtained in the form of scraps or waste, which are usually sold in the form of pellets. It is desirable to obtain these resins in the form of scraps or waste as they are less expensive. Polyethylene milk bottles are the preferred resin source.

Composites may also contain binders. Binders help to bond hydrophilic fibers of polymer-coated paper to hydrophobic resins. Examples of binders are maleic anhydride-modified polyethylenes such as those belonging to the FUSABOND® (manufactured by DuPont, Delaware) and POLYBOND® (manufactured by Uniroyal Chemical, Connecticut) series. A preferred binder is maleic anhydride modified high density polyethylene such as FUSABOND® MB 100D.

The composites may also contain cellulose and lignocellulosic fibers. These fibers add extra strength to the composite. The amount of fiber used in the composite may vary depending on the desired physical and chemical properties of the finished products. Most preferably, the cellulose and lignocellulosic fibers contain from about 5% to about 50%, more preferably from about 10% to about 30% by weight of the composite. Examples of such fibers are paper and paper products, materials of wood origin, as well as materials obtained from kenaf, grass, rice husks, pulp, jute and other cellulose or lignocellulosic materials. The preferred fibers are jute and kenaf. For example, their fiber length / diameter ratio may be at least 10 or at least 25 or 50.

Composites may also contain additives known to those skilled in the art, such as plasticizers, lubricants, antioxidants, opacifiers, heat resistants, paints, impact modifiers, light resistants, flame retardants, biocides and antistatic agents.

Initial preparation of materials

Polymer coated paper cuttings must be cleaned and dried. The polymer-coated paper must be textured before being combined with the resin. Any number of mechanical means, or a combination thereof, may be used to texturize the polymer coated paper. During the texturization process, the polymer layers are separated from the paper layers while exposing the paper fibers. For the best texturization, first, the polymer-coated paper is cut into% -% inch (0.63 - 1.27 cm) pieces using standard paper cutters. These pieces are then cut with a rotating knife as described in Perry's Chem. Eng. Handbook, Issue 6, p. 8-29 (1984) (manufactured by Sprout, Waldron Companies). The textured material is then passed through a 2 mm mesh sieve. Textured polymer coated paper can be stored in sealed bags. It should be immediately 4 to 18 hours before use. dried at 105 ° C (less than about 0,5% moisture content) The drawing shows a photograph of a textured polymer-coated paper under a raster electron microscope.

The resin can be purchased in the form of pills or granules and used without further cleaning or drying. However, if the resin pellets or granules contain moisture, they should be dried before use.

When using cellulosic or lignocellulosic fibers, they can be textured as described above.

Preparation of composites

Composites can be prepared as follows. The standard roller mill with two rubber / plastic shafts is heated to 325 - 400 ° C. The resin (usually in the form of pills or granules) is added to the heated rolling mill. After about 10 minutes, the binder is added to the rolling mill. After another five minutes, the textured polymerized paper is placed in the dissolved resin / binder mixture. The textured polymer coated paper is poured over for about 10 minutes.

'LT 4779 B

The composite is removed from the rolling mill, cut into pieces and allowed to cool at room temperature. It is then pressed into molds using standard injection molding techniques.

Alternatively, a mixer, such as a Banbury household mixer, is filled with ingredients. The ingredients are mixed at a temperature below about 190 ° C. The composite can then be pressurized.

In another embodiment of the invention, the ingredients can be blended in an extruder-type mixer such as a MARIS (Turin) TM 85 extruder with co-rotating screws. The resin and binder are charged through the extruder charging port; the multilayer paper (and the cellulose or lignocellulosic fiber, if used) is loaded into the molten resin at about two-thirds of the length of the extruder. The internal temperature of the extruder is maintained below 190 ° C. Upon discharge from the extruder, the composite is granulated by cold fractionation).

Alternatively, the composite may first be prepared in a mixer and then transferred to an extruder for extrusion and granulation-fractionation operations.

According to another embodiment of the invention, the composite can be made into yarns for knitting, spinning, weaving and weaving and making non-textile articles therefrom. In yet another embodiment of the invention, the composite may be prepared as a film.

Properties of composite

The resulting composites consist of a web of fibers encased in a resin matrix. The fibers on the surface form a grid-like structure that gives the composite strength. Because the polymer coated paper is texturized, the surface area of ​​the resin adhesive is increased compared to non-textured polymer coated paper based composites. The resin adheres to the fiber surfaces accessible to it, closely bonding the fiber web to the resin matrix. The tight binding of the fibers to the resin matrix further strengthens the matrices. Cellulose or lignocellulosic fibers may be added for additional reinforcement of the composite.

Application

Polymer-coated paper / resin composites can be used for a variety of applications. These composites are strong and lightweight; they can, for example, be used as substitutes for wood. The resin coating makes the composites waterproof and can therefore be used outdoors. For example, such composites can be used to make pallets that are stored outdoors for long periods. This composite can also be used, for example, for the production of substrates or frameworks for plywood products. Moreover, the surface of such composites can be machined, grooved, milled, molded, embossed, texturized, embossed, stamped, colored, etc. The surface can be roughened or smoothed.

Examples

The following examples are prepared as follows. A standard mixing mill with two rubber / plastic shafts is heated to 325 - 400 ° C. The resin (usually in the form of pills or granules) is added to the heated rolling mill. After about 10 minutes, the resin adheres to the rolls (ie it melts and adheres to the rolls). The binder is then added to the rolling mixing mill. After another five minutes, add the multilayer paper to the molten resin / binder mixture. Layer paper is placed for about 10 minutes.

The composite is then removed from a rolling mill, cut into sheets and allowed to cool to room temperature. Standard die-casting techniques produce sheets weighing approximately 80 grams and weighing 6 * 6xl / 8 inch (15.24x15.24x0.32 cm).

One composite consists of the following ingredients:

Composite no. 1

Ingredient Quantity, g

High density polyethylene¹ 160

Polymer coated paper² 240

Binder³ 8 ¹ Marlex 6007, alloy flow rate 0.65g / 10min, commercial manufacturer Phillips

Textured using a rotating knife with 2 mm mesh screen ³ POLYBOND® 3009, Commercial Manufacturer - Uniroyal Chemical

The sheets are cut into test pieces of appropriate size and tested in accordance with the test method. Each property of the three individual samples is checked and the mean value of each test is calculated.

Ί

6.83 / 1.22 (ASTM D 638)

6820 (1219 kg / cm²) (ASTM D 638) <5 (ASTM D 638)

12200 (2180.63 kg / cm²) (ASTM D 790)

6.61 / 1.18 (ASTM D 790)

Composite no. 1 features are as follows:

Elastic modulus (10⁵ psi) / (10⁵ kg / cm²)

Tensile strength limit (psi - per square inch) Relative elongation at break (%)

Bending strength (psi - psi)

Elastic modulus of bending (10⁵ psi)) / (10⁵ kg / cm²)

The other composite consists of the following ingredients:

Composite No.2

The Ingredient

High density polyethylene¹Polymer coated paper²Binder³

Quantity, g

160

240 ¹ Milk sachet waste, alloy flow rate approximately 0.8 g / 10 min.

² Textured with a rotating knife with 2 mm mesh screen ³ POLYBOND® 3009

Composite No.2 has the following properties:

5 2

Elastic modulus (10 psi) / (10 kg / cm)

Tensile strength limit (psi - per square inch) Relative elongation at break (%)

Bending strength (psi - psi) <<o

Elastic modulus for bending (10 psi) / (10 kg / cm)

7.38 / 1.32 (ASTM D 638) 6500 (1161.81 kg / cm)²) (ASTM D 638) <5 (ASTM D 638)

11900 (2127 kg / cm²) (ASTM D 790)

6.50 / 1.16 (ASTM D 790)

The third composite has the following composition: Composite No. 3

The Ingredient

High density polyethylene¹

Polymer coated paper²

Binder³

Quantity, g

160

240 s

¹ Milk sachet waste, alloy flow rate approximately 0.8 g / 10 min.

² Textured with a rotating knife with 2 mm mesh screen ³ FUSABOND® MB 100D, commercially manufactured by DuPont

Composite No. 3 has the following properties:

Elastic modulus (10⁵ psi) / (10⁵ kg / cm²)

Tensile strength limit (psi - per square inch) Relative elongation at break (%)

Bending strength (psi - psi)

Elastic modulus of bending (10⁵ psi) / (10⁵ kg / cm²)

7.08 / 1.27 (ASTM D 638) 6480 (1158.24 kg / cm.)²) (ASTM D 638) <5 (ASTM D 638)

10200 (1823.15 kg / cm²) (ASTMD 790)

5.73 / 1.02 (ASTM D 790)

The fourth composite consists of the following ingredients:

Composite No.4

The Ingredient

High density polyethylene¹Polymer coated paper²Binder³¹ Marlex 6007, alloy flow rate 0.65g / 10min.

² Textured with a rotating knife with 2 mm mesh screen ³ FUSABOND * MB 100D

Quantity, g

160

240

Composite No. 4 has the following properties:

t <o

Elastic modulus (10 psi) / (10 kg / cm)

Tensile strength limit (psi - per square inch) Relative elongation at break (%)

Bending strength (psi - psi)

Elastic modulus of bending (10⁵ psi) / (10⁵ kg / cm²)

7.17 / 1.28 (ASTM D 638) 6860 (1226.16 kg / cm)²) (ASTM D 638) <5 (ASTM D 638)

12200 (2180.63 kg / cm²) (ASTM D 790)

7.50 / 1.34 (ASTM D 790)

Other embodiments of the invention are set forth in the claims.