JPH01501540A - Composite film manufacturing method - 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 Composite film manufacturing method Background of the invention Many elastomers are tacky in their untreated or uncured state, or Show the flow. As a result, these materials are bulky as free-flowing pellets. It cannot be transported and must be transported in bales. Therefore, the final Processors need to own bale cutting or crushing equipment. The device is general However, it is large-scale and expensive. In addition, veils are amenable to blending with other substances. It's not easy. Baling is expensive to handle and transport. Elastomer removal For ease of handling and processing, it is desirable to form elastomers into pellets. It has been considered to be good. However, in general, elastomeric pellets have a short shelf life. exhibits "blocking" or cold flow characteristics, especially at warm temperatures, after a , solidifies into a solid mass.

There have been many attempts to make elastomeric pellets that remain free-flowing during processing. It's been coming. Finely powder elastomer pellets with inorganic substances such as clay, talc, etc. It was found that the pellets remained free-flowing for longer periods of time. specific organic substances, such as hydrocarbon waxes (UK Patent No. 901.684) or powder powders; Micronized coating with polyethylene and polypropylene (British Patent No. 928.120) Improvements were obtained by doing so. However, since the differential coverage is discontinuous, The pellets flow together and form a solid mass.

The elastomer is a crystalline polymer, such as polyethylene, polypropylene, or Free-flowing properties achieved by blending with ethylene-propylene copolymer It became possible to produce elastomer-containing pellets.

However, the elastomer content in the pellets should be less than about 65%. made Of course, this product is not suitable for all elastomer applications.

An alternative method of coating is to coat with an emulsion containing a non-adhesive coating. Attempts have been made to coat the last marble. Soak the pellets in the emulsion. Coating is done either by soaking or by spraying emulsion onto the pellets. , the coated emulsion must be dried and the emulsion contains solvent. If so, the solvent must be recovered. Due to the need for drying and solvent recovery, strike rises.

Melt-coatability was also proposed to produce free-flowing elastomeric pellets. . Bishi I! ? U.S. Patent No. 8,869.772, issued to P. According to , coating is performed using a die similar to a wire coating die, and inside this die, The rubber strands to be coated are fed simultaneously with the molten coating material. continuous melting The coated rubber strands are cooled and then pelletized. This melt coating This method not only significantly increases the cost of producing rubber, but also makes large quantities of coated pellets less efficient. There are limits to how much it can be manufactured.

Rubber pellets have been coated with various coating materials. i.e. rubber The pellets are heated to a temperature above the melting point of the coating material, and then the heated pellets are heated to a temperature above the melting point of the coating material. - preferably in powder form. Heated pellets are on the pellet table. As the coating material is melted on the surface, a substantially continuous coating is formed. Then Cool the hot coated pellets.

Studies on binary mixtures have shown that when extruding such mixtures, stratification generally occurs. It happens. [5oulborn, J, H, and Ball*an, R,’L,: 5trat1fied Biocowponent Flow of Polym er Melts in a Tube-, Applied Polymer See 5C11Bnee*No, 20.175-189 (1973). ]author explain that stratification is due to differences in melt viscosity of each component.

Summary of the invention one or more layers of a first plastic polymer and a second polymer as a substrate; A composite film comprising a first plastic polymer and a first plastic polymer composition. About 15% to about 90% by weight of plastic polymer and about 10% to about 85% by weight of *2 polymer % and extrude the resulting mixture through a film die. At least one of the exit surfaces is below the melting point of the plastic polymer at least about This can be done by cooling the formed film (keep it low at 10°C). It was surprisingly discovered that. In a preferred embodiment, the first plus The tic polymer has a semi-crystalline or crystalline melting point, which is higher than that of the second polymer. At least 10°C above the softening or melting point.

By cooling both die exit surfaces, the center of the first plastic polymer and a second polymer, and both outer sides are made of the first plastic polymer. It is possible to make a Santoifuchi-type laminate. blown film die When using a die, both the inner and outer layers of the die must be cooled to achieve the purpose. There is.

In a sheet die, both the upper and lower layers of the die are cooled.

Brief description of the drawing Figure IA shows the scanning electron cross-section of a strand capto pellet cut at liquid nitrogen temperature. This is a microscopic (SEX) photograph.

Figure IB is a SEW photograph of an underwater formed pellet cut at liquid nitrogen temperature.

Figure 2A shows the surface S of a cross section of a strand capto pellet cut at liquid nitrogen temperature. This is an EX photograph, in which the rubber has been extracted from the surface.

Figure 2B is a SEW photograph of the surface of a cross-section of an underwater formed pellet cut at liquid nitrogen temperature. In this case, the surface is made of thermoplastic. ) are continuous and no rubber extraction occurs.

detailed description The present invention relates to a method for manufacturing a composite film. More specifically, the second polymer and A base comprising a first plastic polymer and a first plastic polymer. a composite polymer, the outer surface of which is greater than the first plastic polymer. It is advantageously used to produce a sandwich-type composite film laminate. be able to.

For purposes of illustration, the method of the present invention will be described using a first plastic. However, the book Having reference to the disclosure of the invention, it will be apparent to those skilled in the art to apply the present invention to the manufacture of composite films. It's easy for people.

When practicing the present invention, the elastomer is at least below the softening point of the elastomer. 10°C, preferably at least about 15°C, preferably at least 30°C, more preferably Preferably, a semi-crystalline or crystalline plastic material having a melting point that is at least 40°C higher. Mix with. Next, this blend of elastomer and plastic is passed through a die. extrude In that case, the die exit should be at least 10°C above the melting point of the plastic, preferably or at least 20°C, more preferably at least about 30°C (keep the die cool). A temperature gradient is created from the inlet to the exit of the die.

As the temperature of the melt decreases from the entrance to the exit of the die, the elastomer and The difference in the viscosity of the tic increases, layering occurs, and the plastic It is thought that the elastomer concentration is concentrated along the Ru. Due to its influence on the velocity properties of the two components of the melt, the shear force is influenced by the wall effect (w (alleffect), it also plays an important role in stratification. Therefore, extrusion from the die Compositional differences occur in the melt. The melting point of a polymer is a function of shear force and pressure. In the moving system of the extrusion die, it is higher than the static melting point of the polymer. Statement and error The composition of the stomer and plastic polymer can be applied to a versatile refurbishing device in the manner described above. Multi-orificed 5trand extrusion die extruded using a strand pelletizer or a die front pelletizer. and pelletized. In one embodiment, a conventional strand extrusion die is By deforming, the goo outlet plate is hollowed out and can be cooled with water. In a preferred embodiment In this case, the die is cooled using an underwater pelletizer.

Typical underwater pelletizers include Ga1a Industries Inc. Mini underwater pelletizer (mln) manufactured by (Eagle Rock, Va.) 1 underwater palletzer, MOP).

The layering method to create pellets with plastic-coated surfaces can only be done in a limited amount of time. Therefore, when implementing the method of the present invention, the L/D ratio of the die exit hole is an important index. Become. L/D is about 2 to about 20, preferably about 2.5 to about 12, more preferably It may be from about 3 to about 1O1, for example from about 3.5 to about 8. elastomer and plasti (the inlet diameter is larger than the outlet diameter).

In that case, the L/D ratio is the average exit directness over the length of the channel. Based on diameter.

The length of the exit channel is approximately 2.5 to approximately 10.2 (Jl) (approximately 1 to approximately 4 inches). , preferably from about 1.5 to about 3.5 inches, more preferably from about 1.5 to about 3.5 inches. Preferably about 5.1 to about 7.6 cs (about 2 to about 3 inches), for example about 6.4 cm ( approximately 2.5 inches). The diameter of the Gui exit orifice is approximately 0.1 3 to about 0.51 as (about 0.05 to about 0.200 inches), preferably about 0 ．． 19 to about 0.38 on (about 0.075 to about 0.100 inches), e.g. It may be approximately 0.125 inches.

An important parameter when carrying out the method of the present invention is from the die entrance to the die exit. temperature gradient. Although no specific temperature gradient is required, what is required is at the point where the melt temperature is (preferably close to the melting point of the plastic) This means that it has fallen to almost 100%. Thereby, the viscosity of the plastic melt A large difference between the viscosity of the elastomer melt and the viscosity of the elastomer melt is ensured.

This means that the melting temperature of the composition must be lower than the melting point of the plastic. do not have. However, in preferred embodiments, the melting temperature of the composition is temperature below the melting point of the liquid ingredients. If the method of the present invention is to be carried out, By using an underwater pelletizer and cooling the front of the die, a temperature gradient is created inside the die. make you feel the same

To maximize the temperature differential across the die, operate at or near the closure temperature of the system.

"Occupation temperature" means that a portion of the goo outlet orifice begins to become occluded by solidified polymer. temperature. A degree of blockage in a multi-orifice die can cause the flow rate to become less economical. It is allowed up to 4, which reaches the breaking point. Generally, the outer exit hole of the die becomes obstructed first.

Multi-orifice dao usually has more than 20 outlet holes, for example, 50~10G outlet. It has holes. A die is made at the closing temperature with approximately 20 to 30% of the holes closed. It is possible to move it.

To increase the occlusion temperature, gradually cool the die or the front of the die until the outlet hole begins to become obstructed. Cool to the point where it melts. Extrusion at the closure temperature results in stratification and elastomer pellet formation. The formation of the plastic surface layer in the cut is the best.

When using an underwater pelletizer, the cooling water temperature is about 20 to about 50°C. "Press The exit melting temperature (die inlet melting temperature) is approximately 160 to approximately 250°C, and the Varies depending on the elastomer and plastic used. Various plastics - Nylastoma - Suitable extruder melt temperatures for the compositions are known to those skilled in the extrusion art.

The method of the invention is particularly suitable for elastomers that are tacky in the solid state or exhibit cold flow. ing. A non-limiting example of an elastomer to which the method of the present invention can be applied is a High molecular weight elastomers such as ethylene-propylene rubber (EPR) , terpolymer of ethylene, propylene and non-conjugated diene (EPDM), natural Rubber, polyisobutylene, butyl rubber, halogenated butyl rubber, acrylonitrile These are rub-butadiene rubber (NBR) and styrene-butadiene rubber.

Plastics that can be used in the practice of this invention are crystalline melts at a temperature of at least 70°C. Has a point. An illustrative example of such a plastic polymer is high-density polyethylene. (HDPE), low density polyethylene (LDPE), polypropylene (PP) ), LLDPE, syndiotactic polybutadiene resin (SBD), poly There are crystalline copolymers of butene-1, ethylene and other α-olefins. plus The tick and elastomer must be insoluble in each other in the molten state.

The elastomer/plastic polymer composition of the present invention comprises a plastic polymer from about 15 to about 90% by weight, such as from about 20 to about 80% by weight. Desired product is an elastomeric product, the plastic polymer makes up about 15% of the composition. ~35% by weight, preferably from about 15 to about 30%, most preferably from about 2D to about It accounts for 28% by weight, for example about 25% by weight.

Plastics and polymers can be blended by any conventional method; Supplied to the exit machine. For example, shred elastomer veils and ribbon blending inside, it can be mixed with plastic polymer powder and then fed to an extruder. . Preferably, a mixing extruder, for example a twin-screw extruder, is used for extrusion, Complete mixing of tomer and plastic is possible. Mixture It is extruded through a thiorifice die, but in that case, the front side of the gou is made of plastic polymer. Keep the temperature below the melting point (approximately 10°C below). Preferably, the die front is covered with plastic. The temperature is at least about 10°C below, and about 30°C below, the melting point of the polymer.

Of course, considering the high melting temperature of the polymer, it is difficult to maintain the entire die plate at a single temperature. The die has a temperature gradient from the internal inlet surface to the outer front surface of the die exit. .

In order to demonstrate the effects of the present invention, elastomers and plastics having the compositions shown in Table 1 were used. The polymer composition is extruded through a conventional multi-orifice strand extrusion die. The polymer strand thus obtained was cooled through a water bath. Then Stra pelletized. Furthermore, the same composition was pelletized using an underwater pelletizer. It became.

It has a lower friction coefficient and higher free-flowing properties than pelletized strands. Ta. Table ■ shows a comparison of the friction coefficients of the above two products, and Table ■ shows the pressure/strength of both sets of acids. Show the ratio. The pressure/intensity ratio under the shear force required to produce pellet flow It is the ratio of cohesive pressure to yield strength at The larger the ratio, the more free-flowing the pellet is. Larger elastomer/plastic compositions Elastomer *l: 40% by weight plastic polymer HDPE”: 16 weight 96 Polypropylene H, 44% by weight Ne1 Ethylene content 43%, glass transition temperature 55℃, Mooney viscosity (1+8.1 27° C.) 25 ethylene/propylene copolymer.

Ne2 AB 55-1oo, HDPE polymer with melt index 10.

Ne3 Table of propylene and ethylene with a crystalline melting temperature of 160℃ ■ A Traditional strand cut 2222 B underwater cut 1318 (surface) Table ■ A 27.1 (38B) 659 (135) 2.498 19.1 (2 72) 8g (1B) 15.1 In making underwater cut pellets of the present invention The MUP was operated at an extrusion psi) and a cooling water temperature of 40.6°C (below 105).

The extrusion speed of the extruder was 8.8 kg/hour (125 ibs/hour).

As is clear from the above data, the pellets made by the method of the present invention are Even if the compositions of both are the same, they are more free-flowing than those that have been made into pellets. Figure I A and IB are S of strand-cut pellets and underwater-cut pellets, respectively. This is an EW photo. The rubber phase of the composition was extracted with hexane. As can be seen from the photograph in Figure IB Therefore, the product made by the method of the present invention has a surface consisting essentially only of plastic polymer ( skin). On the other hand, strands made into pellets are essentially uniform. It is the composition.

To indicate that the surface of the pellet of the present invention consists essentially of plastic polymer. First, the pellets were treated with hexane to extract the rubber phase. A comparison between Figures 2A and 2B As shown, rubber was extracted from the surface of conventional strand-cut pellets, but There was virtually no rubber extraction from the surface of the pellets made according to the method of the invention.

Relating to a method for producing elastomer-coated pellets with a plastic polymer surface However, as is clear from the following description, the method of the present invention has only one effect. Used for manufacturing polymer films consisting of a laminate of one polymer machine and another polymer machine. I can. Alternatively, the method of the present invention allows both sides of one polymer machine to be used with another polymer machine. It can be used to produce sandwich sandwich bodies.

As an indication of the production of such films, the first polymer, in the molten state, is It is necessary to be insoluble in the remer, and in addition, the difference in the softening or melting points of both polymers is required. is at least 10°C, preferably at least about 30"C1, preferably less than The temperature is at least about 40°C. I want to form a “surface J” (skim) of a composite film. The polymer needs to have a higher melting point. − When describing the present invention in terms of free-flowing pellets, the core of the pellet is generally It's a streamer. The second polymer constituting the film adheres to the above-mentioned criteria. However, it does not have to be an elastomer.

The film can be manufactured using conventional film forming techniques such as blowing, casting, or can be carried out using the tubular water bath method. At least one table of composite material In order to form 5kin on the surface, it is necessary to cool the die surface using the method described above. .

Blown film using “A” frame and nip Roli Using traditional manufacturing methods, it is necessary to surround the film bubble and cool it. The extruded blown film can be cooled using an annular water bath. By water cooling cooling the front surface or using a water-cooled mandrel for blown film extrusion. This method by cooling the drell and then cooling the inside lip of the die exit. can be corrected.

Similarly 1. A coated film can be produced using a slit die. die out When only the upper or lower lip of the mouth is cooled, a film consisting of two layers, i.e. The plastic layer and the elastomer or '! J2 plastic layer film is formed. If both die lips are cooled, make sure both outer sides are plastic. Polymers, Sunglasses whose inner core is an elastomer or a second plastic polymer A German body is manufactured.

In another aspect of the invention, a chemical blowing agent is incorporated into the second plastic polymer. can do. Alternatively, a physical blowing agent such as Freon may be added to the extrusion melt. It can also be injected. The resulting product is made of plastic polymer between two surfaces. It will have a foam core.

In other embodiments, the elastomer is a tackifier resin, such as a terpene resin. Blend with to make a pressure sensitive or melt adhesive. Cool only one side of the mouth outlet lip. Ru.

The resulting product is a plastic polymer coated with an adhesive, useful for covering walls or shelves. It becomes a film that has been reversed.

When the elastomer/plastic polymer composition has the composition of Table I, the surface The core is a heat-sealable plastic and the core is a flexible elastomer. A rhinoceros body is produced. This product is a flexible packagingop Eratton 1 is useful for example in medical solution bags.

In addition to the plastics mentioned above, other polymers such as thermoplastic polyester, The coated film of the present invention is manufactured using cross-linked polymers, PVC, etc. be able to. Examples of ionic crosslinked polymers include sulfonated EPDM, ethylene Mention may be made of carboxylic acid polymers or carboxylic acid copolymers of styrene.

FIG. 1B FIG, 2A FIG, 2B Procedural amendment (voluntary) October 7, 1986

Claims (13)

[Claims] 1. one or more layers of a first plastic polymer and a second polymer and a first plastic polymer; In a method for producing a composite film comprising a base of a composition with a plastic polymer , the plastic polymer is 10°C or more higher than the softening point or melting point of the second polymer. the first plastic polymer has a semi-crystalline or crystalline melting point; from about 15 to about 90% by weight of the composition of the first plastic polymer and the first plastic polymer; The polymer of No. 2 and the plastic polymer are mutually insoluble, and the manufacturing method comprises: (a) homogeneously mixing a second polymer and a first plastic polymer; (b) Transfer the resulting mixture to a die exit consisting of a first die surface and a second die surface. Extruded from a film die with (c) at least one surface of the die exit is heated to a temperature below the melting point of the plastic polymer; and cooled to a temperature about 10°C or more lower, (d) Cooling the obtained film A method for producing a composite film, which consists of the following steps. 2. The method of claim 1, wherein the first plastic polymer is from about 15 to about 60% by weight of the composition of polymer No. 2 and first plastic polymer. How to account for. 3. The method of claim 2, wherein the first plastic polymer is from about 15 to about 35% by weight of the composition of polymer No. 2 and first plastic polymer. How to account for. 4. The method of claim 1, wherein the second polymer has a T of less than 0°C. An elastomeric polymer having g. 5. In the method according to claim 4, the elastomer is EPR or EPDM. , NR, SBR, PIB, halobutyl rubber, or mixtures thereof. 6. The method according to claim 4, wherein the plastic polymer is HDPE. , LDPE, LLDPE, polypropylene, polybutene-1, crystalline ethylene- α-olefin copolymers, or mixtures thereof. 7. In the method according to claim 4, the elastomer is EPR or EPD. M, and the plastic polymer is a crystalline ethylene-propylene copolymer, HD PE or mixtures thereof. 8. The method according to claim 4, wherein the plastic polymer is a sulfone. EPDM ionomer or poly(ethylene glycal terephthalate) ,Method. 9. In the method according to claim 4, the elastomer is combined with a tackifier resin. in combination to form a pressure sensitive adhesive composition having elastomeric properties. That's the way it is. 10. The method of claim 9, wherein the die has inner and outer die lips. It is a blown film die with an annular outlet with an inner die lip of The method by which the water is cooled. 11. The method according to claim 4, wherein the elastomer is ethylene-propylene. It is a pyrene copolymer, and the plastic polymer is HDPE and crystalline ethylene copolymer. A method of blending with a ropyrene copolymer. 12. The method according to claim 11, wherein the elastomer, HDPE and Crystalline ethylene-propylene copolymers are used as elastomers/plastics, respectively. Methods comprising about 40%, about 16% and about 44% by weight of the composition. 13. In the method according to claim 1, the first die surface, the second die surface How both sides are cooled.