JPH06509528A - heat seal products - 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: Heat seal product This application is filed in U.S. Application Nos. 252.094 and 199, filed September 30, 1988. This application is a continuation-in-part of U.S. Application No. 732,865, filed July 18, 2016.

Technical field The heat sealing portion of the present invention is made of a copolymer or a blend thereof. Regarding heat seal products such as. More specifically, the present invention has a narrow composition distribution. Copolymer compositions and copolymer blends comprising a copolymer with a narrow molecular weight distribution Regarding the composition. The copolymers of the present invention, especially the copolymer blends, have heat sealability. It also has excellent other physical properties. Copolymers of the present invention and their polymers Lend is used for films, bags, pouches, tabs, trays, lids, and packaging materials. It can be used to produce containers, containers, and other products that use heat-sealing materials. .

Background of the invention There are many industrial products on the market that use heat-sealing materials. In general, Seals on such products are used by welding two separate parts of the product. example For example, plastic parts used in machinery and toys are made up of two separate plastic parts. Heat one or both of the bonding sections, crimp them together, then allow to cool to bond these two sections together. It can be made by joining plastic parts together. Especially the heat seal Very important in packaging applications. Packaging materials made of heat-sealing materials are Promote more efficient transportation of consumer goods wrapped in Packaging materials are also used in the food industry to preserve the freshness of consumer goods. There is.

Various types of weights that can be joined or sealed by applying heat and/or pressure. Consolidation is used in a variety of products, including packaging materials. used in the manufacture of such products. The polymers or polymer blends used can be prepared by applying heat and/or pressure once for a short period of time. selected depending on the application to form a strong seal easily and quickly. It will be done. In some cases, heat-sealed products from the same polymer or polymer blend Sometimes the whole thing is made. However, using different materials in various parts or layers, Polymers that exhibit good heat sealing properties are suitable for areas where heat sealing is really required or More often, it is used only in layers to manufacture products.

This manufacturing method is used because the product (e.g. multilayer film) is heat-sealed. Desirable physical and mechanical properties such as clarity, strength, puncture resistance, and tear resistance, as well as transparency, It must have mechanical properties and be easily processed using high-speed equipment. It is. Many plastic materials with good physical and mechanical properties are known. However, there are few that also have good heat sealability. For example, polypropylene has good strength and transparency and is resistant to tearing, but It is not easy to create a good seal over a suitable temperature range for a given device. On the contrary, good Polymers with heat-sealing properties do not have sufficient strength or transparency.

Therefore, in the technical field of packaging materials, it is necessary to - or one or more layers of different types of polymers to provide good heat sealing to the product Multilayer products have been developed, such as multilayer films that add one or more layers to provide It's been coming. The film is thus coated with polypropylene to give it strength and clarity. It has a lopylene base layer and a polyethylene layer to provide good heat sealability. It can be made to look like this. Other products besides film are similarly made from multiple materials. The individual materials can have one or more of the desired properties in the final product. selected to contribute to the above.

Various types of polyethylene polymers have acceptable heat sealability is publicly known. Low density polyethylene (LDPE) generally uses a radical initiator. manufactured at high pressure and with a density typically in the range of 0.915 to 0.940 g/c1 have. LDPE, also known as "branched" polyethylene, is a heavy This is because a relatively large number of long branched chains extend from the combined main chain.

High density polyethylene (HDPE) is usually 0.940g/cm3 to 0.960g /cm'. HDPE is a Ziegler-Natsuta catalyst-like arrangement. It is produced at low to medium pressure using a catalyst, but it may also be produced at high pressure.

HDPE is generally linear and substantially free of side chain branching.

HDPE is a substantially crystalline polymer.

Linear low-density polyethylene (LLDPE) is generally manufactured in the same way as HDPE. However, relatively small amounts of α-olefin comonomers ( butene, hexene, octene, etc.) into polymers that would otherwise be linear. As a result, the density of the resulting polymer is reduced to the same extent as LDPE.

Coordination catalysts used in the copolymerization of ethylene and α-olefins are generally defined below. The defined composition distribution is wide and the molecular weight distribution is relatively wide, that is, Mw/Mn is About 3 or more (where Mw is the weight average molecular weight and Mn is the number average molecular weight) of LLDPE.

Industrial polymerization processes simultaneously produce a huge number of polymer molecules. Polymer molecules produced They do not all have exactly the same molecular weight. In addition, there are comonomers Even when do not have. As used herein, the terms "polymer" and "copolymer" refer to substantially one made from a catalyst having substantially the same composition and structure under the same polymerization conditions. refers to a group of polymer molecules. Therefore, two polymers are produced from different types of catalysts. or if they are made from the same catalyst but their polymerization conditions are different. If different, these polymers are different from each other.

Polymerization conditions include not only polymerization temperature and pressure, but also the species of comonomer, if present. It includes the type and amount, as well as the amount of hydrogen, if present.

It is known in the prior art that copolymers have a relatively wide compositional distribution. joint weight The relatively wide compositional distribution of the aggregate is due to the α-olefin incorporated into individual polymer molecules. This is because the number of comonomer molecules is different. Generally, relatively low molecular weight polymer content The particles contain relatively large amounts of α-olefin comonomers, and contain high molecular weight polymers. The alpha-olefin comonomer content of the child is relatively low. Heavy duty with low comonomer content Although the coalescing molecules are relatively crystalline and have a high melting temperature, they are The combined molecules are highly amorphous and melt at low temperatures. The presence of components with too high a melting temperature It is not beneficial for many applications, such as those requiring heat sealing. Conversely, The presence of large amounts of comonomers in the low-melting components results in large amounts of extractables (i.e. (low molecular weight polymers that are soluble in solvents such as pentane and pentane) and are Use in applications that involve contact is restricted.

Conventionally, polyethylene such as LLDPE also has a wide molecular weight distribution, and many There were some inconveniences. For example, the previously known LLDPE resin Because it contains relatively high molecular weight molecules that are attached, it is difficult to The result is anisotropy in the longitudinal direction. Such high molecular weight molecules are comonomers It has a low content and lacks sufficient heat sealability. On the other hand, relatively low molecular weight molecules All resins that contain comonomers are concentrated in comonomers and have excellent heat-sealing properties. However, it tends to exhibit high blocking and adhesive properties. such a low Molecules with high molecular weight and high branching also make it difficult for certain additives to be incorporated into the resin. inhibits positive functions, increases the proportion of extractable polymers, and increases fouling of the polymerization plant. let Such low molecular weight polymer molecules are characterized by their α-olefin comonomer content. Because of the relatively high amount, it generally becomes amorphous and leaches onto the surface of the fabricated product, resulting in the desired It gives an undesirably sticky surface.

Conventionally known polyethylene blends containing the blend components or conventional polyethylene blends. Blends devised to improve properties compared to - or even better than - homopolymers. The above-mentioned drawbacks can also be seen with regard to the For example, reduce crystallinity and heat seal It is common to incorporate blend components with high average comonomer content to improve properties. This results in an increase in extractables and adversely affects other physical properties. You won't get the full benefit of Lend.

Furthermore, in international application WO9010314 published on April 5, 1990, Copolymer blends made from multiple components with narrow molecular weight distribution and narrow composition distribution is disclosed. This publication also states that such blends have tear strength and tensile strength. It is vaguely stated that qualities such as strength may be improved. However, a commercially advantageous temperature range from a selected group of ethylene copolymers and blends. and temperature and contact pressure conditions that allow for the formation of a good seal during processing time. What about the unexpected discovery that heat-sealed products can be manufactured under This publication does not contain any information that may be helpful or suggestive. .

Conventionally, as mentioned above, until the present invention, the comonomer distribution of the polymer was made uniform, Such polymers and blends thereof have excellent heat-sealability and No comparable method has been found to preserve other desirable physical properties. did Therefore, ensuring proper and uniform distribution of comonomer throughout all polymer molecules A selected polymer or polymer blend is needed.

Summary of the invention The present invention each has a narrow molecular weight distribution and a composition distribution width index (compos) of 50% or more. itional distribution breadth index) Excellent heat sheets made from copolymers and blends of these copolymers Concerning products that exhibit compatibility. In particular, single-layer or multi-layer fibers used in various packaging applications. The above copolymers useful in the production of ethylene may be ethylene copolymers; A blend of ren copolymers may also be used. Individual ethylene copolymer groups have narrow molecular weight distributions and has a narrow composition distribution. Specifically, such special ethylene copolymers and These blends can be used to obtain heat-sealable or heat-sealable products of the present invention. selected to provide superior properties. Broadly used in the products of the present invention The blend comprises a plurality of linear ethylene copolymer components, each of which has a It has a composition distribution breadth index (CDBI) (described later) of 50% or more. "Narrow composition" The expression "cloth" or "narrow CDJ" is used herein to mean a CDBI of 50% or more. used to represent a polymer with Preferred heat-sealable polymeric blends The polyethylene resin has a higher average molecular weight and lower average copolymer than the other polyethylene components in the blend. It is substantially free of blend components that also have a blend component. each blend The components of You can choose to have multiple modalities for both. Ru.

In another embodiment, the components of the blend have a narrow molecular weight distribution and a narrow composition as described above. These blend components are linear ethylene copolymers with a distribution of the following group = ( 1) A plurality of molecules having substantially the same average molecular weight but different average comonomer contents. ethylene copolymer blend components, (2) having substantially the same average comonomer content; a plurality of ethylene copolymer blend components having but different average molecular weights, and (3 ) Multiple linear ethylene copolymer blends with different average molecular weights and comonomer contents and the blend components are arranged in order of increasing average molecular weight. selected from those in which the comonomer content gradually increases.

In yet another embodiment, the linear ethylene copolymer blend component is a narrow molecular These linear ethylene copolymer blend components have the amount and composition distribution described above. If arranged in order of increasing average molecular weight, each subsequent component will have a It has an average comonomer content that is substantially the same as or higher than that of the previous component.

In another aspect, the present invention has multiple aspects regarding comonomer content; Narrow molecular weight distribution such that Mw/Mn≦3 and 50% overall blend A heat-sealable linear ethylene copolymer blend having a composition distribution width index of less than provide

In yet another aspect, the present invention provides linear ethylene with multiple modalities regarding molecular weight. As a copolymer blend, the blend as a whole has M w / M n > 3. Linear ethylene copolymerization with a wide molecular weight distribution and CD81250% Serve body blend.

In yet another aspect, the present invention provides both comonomer content and molecular weight. to make a blend of linear ethylene copolymers with multiple aspects, and adjust the Mw/M of each component. It has a narrow molecular weight distribution where n is 3 or less, and each component is added to increase the average molecular weight. A plurality of components whose average comonomer content increases gradually when arranged in the order of addition. A linear ethylene copolymer blend comprising:

In yet another aspect of the invention, both comonomer content and molecular weight A linear ethylene copolymer blend with multiple aspects, with a composition of 50% or more Contains a plurality of components having a cloth width index, and combines these components with an average comonomer content. Linear ethylene whose average molecular weight gradually increases when arranged in a direction with increasing ratio A copolymer blend is provided.

To make a heat seal product of the present invention, at least two parts of the product are Press together at a temperature sufficient to soften at least one of the parts. Bye. The product parts that are thus heat softened have a CDBI of 50% or more. an ethylene copolymer or a plurality of such ethylene copolymers as a blend component; made from a polymer blend comprising: heated to form a heat seal Only one part of the product that is pressed is ethylene copolymer or ethylene copolymer. It is sufficient if it is made from a blend, but the product department directly involved in heat sealing Preferably, all of the components are made from ethylene copolymers or blends thereof. Yes.

In one embodiment, the heat-sealed product manufactured in this way has a main body and and a sealing member fixed to the container, wherein the sealing member is narrow. Ethylene copolymers with a narrow compositional distribution as well as multiple such ethylene copolymer compositions. in a container containing a sealing layer comprising one of the group consisting of a blend of be.

In one embodiment, the heat sealable product of the present invention has a CDBI of 50% or more. and ethylene copolymers with narrow molecular weight distribution or as blend components. A film comprising a polymer blend comprising an ethylene copolymer. .

The present invention has heat-sealing properties such as those used for the above-mentioned heat-sealing applications. Copolymers and copolymer blends, blends of multiple linear ethylene copolymers Components, each component is narrow enough that Mw7Mn is 2.5 or less Copolymers and copolymers having a molecular weight distribution and a composition distribution width index of 50% or more Also included are polymer blends. The above blend ingredients are (1) Blends with substantially the same average molecular weight but different average comonomer content (2) the average comonomer content is substantially the same, but the average molecular (3) different amounts of blend components, or (3) different average molecular weights and comonomer contents. If the components are arranged in order of increasing average molecular weight, the comonomer content can be increased. progressively increasing blend components, or (4) Combination of these selected from the group consisting of. However, the density of the above copolymer blend is 0.875 ~0,94 g/c+o3.

Brief description of the drawing The above aspects, features, and advantages of the invention will be apparent from the following detailed description together with the accompanying drawings. It will become clearer and more fully understood as you read it. In the attached drawings, Figure 1 shows poly(ethylene-two α-olefin) with narrow molecular weight distribution and composition distribution. 1 is a schematic illustration of various blends made from blend components. FIG.

Figure 2 shows the breadth of the molecular weight and composition distributions of typical prior art LLDPEs. FIG.

FIG. 3 shows the narrow molecular weight distribution and narrow composition distribution of exemplary blend components used in the present invention. FIG.

Figure 4 shows that the blend components have approximately the same molecular weight but different comonomer contents. Molecular weight distribution and composition of an exemplary LLDPE blend according to one embodiment of the present invention: FIG.

Figure 5 shows that the comonomer content is approximately the same among the blend components, but the molecular weights are different. The molecular weight distribution of an exemplary LLDPE blend according to another embodiment of the invention, and It is a schematic diagram about composition distribution.

Figure 6 shows that as the molecular weight increases among the blend components, the comonomer content also increases. Molecular Weight Distribution of Exemplary LLDPE Blends According to Yet Another Embodiment of the Invention and a schematic diagram of composition distribution.

Figure 7 shows the relationship between seal temperature and seal strength for films made from prior art polymers. FIG.

Figure 8 shows the relationship between sealing temperature and sealing strength of films produced according to the present invention. This is a graph showing.

Figure 9 shows the relationship between sealing temperature and sealing strength of films produced according to the present invention. This is a graph showing.

Figure 10 shows the relationship between sealing temperature and sealing strength for films produced according to the present invention. FIG.

Figure 11 shows the relationship between sealing temperature and sealing strength for films produced according to the present invention. FIG.

Figure 12 shows the relationship between sealing temperature and sealing strength for films produced according to the present invention. FIG.

FIG. 13 is a sectional view of the sealed container of the present invention.

FIG. 14 is a cross-sectional view of the film, lid, or seal member of the present invention.

Figure 15 shows a narrow copolymer (X) of SDB I and CDB I and a narrow copolymer (X) of SDB I and CDB I. 1 is a graph showing the solubility distribution and composition distribution of the wide copolymer (Y) of CDB I and Ru.

Figure 16 shows the relationship between melting temperature and composition, which was used to convert the temperature scale into a composition scale. This is a graph showing.

FIG. 17 is a graph illustrating a method of calculating CDBI.

Detailed description of the invention Even if the linear ethylene copolymer of the present invention is an ethylene homopolymer, the majority of the ethylene copolymer contains ethylene. It may also be a higher order copolymer of ren and a small amount of comonomer. When using comonomers generally 70 to 99.99 mol% based on the total monomers to be copolymerized, Typically 70-97 mol%, often 70-80 or 80-90 or is 83 to 99.99 or 90 to 95 mol% of ethylene, o, oi to 30 mil 30 mol 3-30 mol%, often 20-30 or 10-30 mol% Polymerized with 20 or 0.01 to 17 or 5 to 10 mol% comonomer Ru. Possible blend components have a density in the range of 0.85 to 0.96 g/cm'. It has a density of 0.875 to 0.900 g/cm' in general. Stomer-based blend components, extremely dense with a density range of approximately 0.900 to 0.915 g/cm3 a polyethylene-based blend component with a low density, and a density range of about 0.915 to 0.9 Contains 40 g/cm3 of linear low density polyethylene based blend component. Approximately 0.9 Ethylene with a density in the high density polyethylene range exceeding 40g/am' It is believed that polymers may also be suitably used in the present invention.

Comonomers suitable for copolymerization with ethylene to obtain the above ethylene copolymers include: Can be copolymerized with ethylene to provide the desired comonomer distribution in the blend components. Contains monomers such as Preferred types of comonomers have 3 to 1 carbon atoms. 2 α-olefins, such as propylene, 1-butene, 1-pentene, 1 -hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-octene These include ten, 1-decene, and 1-dodecane. Other preferred comonomers include , vinylcyclohexane, norbornene, vinylcyclohexene, and others diene comonomers such as 1,3-butadiene, 1,4-hexadiene, 4 -Methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1.5 -Includes hexadiene, etc. Ethylene copolymers contain one or more such comonomers. may contain more than that, in other words, it may be a binary copolymer or a tertiary copolymer. It may also be a combination.

The molecular weight of the above ethylene copolymer ranges from 1,000 to 1,000,000 or more depending on its end use. It can vary up to 104 to 106, particularly 2X10' to 5X10 It is 5.

As used herein, the terms "average molecular weight" and "molecular weight" are used unless otherwise specified. weight average molecular weight. The molecular weight of the produced polymer is determined by adding it to the polymerization reaction. It can be varied by adjusting the amount of hydrogen. In general, hydrogen concentration When the hydrogen concentration is low, high molecular weight polymers are obtained, and when the hydrogen concentration is high, low molecular weight polymers are obtained. is generated. Therefore, if the amount of hydrogen is selected appropriately, a polymer with the desired molecular weight can be produced. can be done.

The above ethylene copolymer preferably has a composition distribution breadth index (CDBI) of 50% or more. , more preferably 60% or more, most preferably 70% or more Has cloth (CD). CDBI is the median total comonomer molar content (median 50% range of total molar commoner content) is defined as the weight percent of an ethylene copolymer having a comonomer content within . For example, the median total comonomer mole content of a group of ethylene copolymers is 4 moles. %, CDB I of such copolymers contains 2 to 6 mol % of the comonomer. -% by weight of the ethylene copolymer having a molar concentration. If this ethylene copolymerization If 55% by weight of the body group has a comonomer molar content in the range of 2 to 6 mol% , its CDB I is 55%. Linear polyethylene alone without comonomer The CDBI of the polymer is defined as 100%. The copolymer CDB I is, for example, Patent No. 5.008.204 or W i 1 d et al., J.

Poly, Sci, Poly, Phys, Ed.

vo 1.20. p, 441. (1982) etc. It is easily calculated from data obtained by any known technique. The contents of both documents above are is incorporated herein by reference.

The solubility distribution was determined by filling non-polar glass beads (20-3o mesh) and ID (inner diameter) 1, 8 cm with a length of 164 cm immersed in a programmable oil bath. Measured using a column. This oil bath is non-conductive to minimize temperature gradients within the oil bath. It is constantly stirred vigorously and the oil bath temperature is measured with a platinum resistance thermometer. Approximately 1.6 g of polymer was placed in a sample preparation chamber, and the system was removed by repeatedly degassing and introducing nitrogen. Remove oxygen. Add a measured volume of tetrachlorethylene to the sample preparation chamber The polymer solution with a concentration of about 1% was prepared by stirring and heating at 3 atm and 140°C. obtain. A measured volume (1,00 cc) of this solution was then heated to an elevated temperature (120°C ) into the above-mentioned packed column whose temperature is controlled.

The column was then cooled to 0°C at a cooling rate of -20°C per minute. , crystallize the polymer solution in the column. The column temperature is 2 to this temperature (0'C). Hold for 5 minutes. The pure solvent, which had been preheated to the temperature of the oil bath, was then added at a rate of 27 min. Begin the elution step by flowing through the column at a flow rate of cc. from the column The eluate is sent through a heating line to an IR detector that detects the eluate stream. Measure the absorbance. of the C-H stretching vibration band of the polymer at about 2960 cm''I The absorbance is a continuous measure of the relative weight percent concentration of the polymer in the eluate. red After passing through the external detector, the temperature of the eluate was lowered to approximately 110°C, and the pressure was lowered to atmospheric pressure. After separation, the eluate stream is sent to an automatic fraction collector. Fractions were collected at 3°C intervals. I can't stand it. In the above elution step, pure tetrachloroethylene solvent was heated to 0°C. and run through the column for 25 minutes at a flow rate of 27 cc per minute.

This procedure washes out the uncrystallized polymer from the column during the crystallization step. From the infrared absorption trace (record), the proportion of amorphous polymer (i.e., 0°C (proportion of polymer dissolved) can be calculated. Then, at a rate of 1.0°C per minute, Program the temperature to increase to 20°C. Thus, the solubility distribution curve ( i.e., the weight fraction of dissolved polymer is plotted as a function of temperature). can get.

solubility distribution width index The calculation method for dthindex (abbreviated as S　D　BI　I) is as described below. be.

FIG. 15 shows the solubility distribution of two types of ethylene copolymers. Here we are just looking at an example. Sample X has a narrow solubility distribution compared to sample Y, which has a wide solubility distribution. It elutes in a narrow temperature range. Solubility distribution breadth index (SDBI) is the solubility distribution curve used as a measure of width. The weight fraction of the polymer that dissolves (dissolves) at temperature T is v (T). The average melting temperature T1 is given by the following equation.

T,ve=　f　Tw(T)dT However, J v (T) dT = 1.

SDB I is calculated using the following relational expression.

5 DBI (℃) =' -ave W (Thus, 5DBI is similar to the standard deviation of a solubility distribution curve, but (T- The difference is that it involves the fourth power of T, , , ) instead of the square. ) For example, the solution shown in Figure 15 The SDB I values of sample X with a narrow solubility distribution and sample Y with a wide solubility distribution are each 14. ．． 6°C and 29.4°C.

A preferred value of SDB I is less than 28°C, more preferably less than 25°C. The temperature is even more preferably lower than 20°C.

The composition distribution (CD) of a crystalline copolymer can be determined as follows. Several types of poly( The composition and composition of each component of ethylene-coptene) collected at various narrow temperature intervals. and number average molecular weight (Mn) by 13CNMR and size exclusion chromatography, respectively. It was measured with Figure 16 shows the elution temperature versus elution temperature for fractions with Mn > 15,000. Figure 2 is a plot of mole % comonomer. Using a curve drawn through the measurement points, 0 Determine the correlation between elution temperature and composition for temperatures above ℃. The Mn of the fraction is 15 When the value is lower than 000, the correlation between elution temperature and composition becomes less accurate. this Such errors can be eliminated by directly measuring the composition of the eluate fraction using CNMR. can be done. Alternatively, as an alternative method, elution for the high molecular weight fraction shown in FIG. The temperature-composition calibration curve was calculated using the Mn of the elution fraction as well as the experimentally determined Mn<15000. Correction may be made based on the correlation between Mn and elution temperature. but, Such low-molecular-weight molecules exist in negligible amounts, and even if the error Even if it occurs, it is considered to be negligible. The calibration curve shown in Figure 16 looks like It can be applied to any random poly(ethylene-two α-olefin), but only However, there is a condition that the α-olefin in this case is not propylene.

In this way, the temperature scale of the solubility distribution plot can be converted to a composition scale to calculate the polymer weight. A fraction versus composition curve can be obtained. As is clear from the composition scale in Figure 16, The molecules contained in sample X are in a narrow composition range, but the molecules contained in sample Y are in a wide range It spans a wide composition range. In this way, although sample X has a narrow composition distribution, On the other hand, sample Y has a wide composition distribution.

A quantitative measure of the width of the composition distribution is given by the Composition Distribution Breadth Index (CDBI). It will be done. CDB I is the median comonomer composition (median value of comonomer composition) It is defined as the percentage of the polymer that has a composition within the 50% range. CDB I is the composition distribution curve and the normalized accumulation of the composition distribution curve, as shown in FIG. Calculated from the value.

The median composition Cヮ,6 is equal to the composition for which the cumulative value is 0.5.

0.5X (,,,,difference in cumulative value between composition of d and composition of 1. (in this example, 71-29, or 42%) is the copolymer CDBI. Ru. CDBI values range from 0 to 1, with higher values indicating a narrower CD. A small value means that the CD is wide. Referring again to Figure 15, in the Book of Testament The narrow CD and wide CD copolymers are 95.5% and 42%, respectively. CDB has an I value. CD and CDB of copolymers with very low comonomer content It is difficult to measure I with high precision, so the density exceeds 0.94 g/cc. The CDBI of polyethylene produced is set as 100%. "Comonomer content", "average "uniform comonomer content" and similar terms refer to the ethylene content unless otherwise specified. The bulk comonomer content of the copolymer is shown on a molar basis.

The ethylene copolymers of the present invention have a narrow molecular weight distribution (MWD). “Narrow MWD The term J means that the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) is 3. It means less than or equal to 0. Particularly preferred is ethylene with a very narrow MDW. copolymers, i.e. having a Mw/Mn of 2.5 or less, particularly a Mw/Mn of about 2 or less It is an ethylene copolymer. The molecular weight distribution of the ethylene copolymer can be determined using known techniques (e.g. size exclusion chromatography, etc.).

FIG. 3 graphically shows specific examples of ethylene copolymers with narrow MDW and CD. child In the three-dimensional diagram, the Y axis is the molecular weight and the X axis is the comonomer molar content. , the Z-axis represents the frequency or weight ratio of molecules. In Figure 3, M of the ethylene copolymer It can be seen that DW and CD appear as narrow and relatively sharp peaks. contrast Generally, the MDW/CD for a typical conventional LLDPE as seen in FIG. The figure shows a wide MDW and a wide CD, and as the molecular weight increases, the comonomer -The content tends to decrease. In each blend of the invention, CD and MD By appropriately selecting and combining narrow W ethylene copolymer blend components, - or more properties of the blend are improved. In one embodiment, e.g. For example, multiple linear molecules with approximately the same average molecular weight but different average comonomer contents Tear strength can be adjusted by blending polyethylene resin . Such a blend is illustrated as line B in FIG. In another embodiment, A common line of linear polyethylene blend components, as illustrated in Figure 1 as line C. The polymer content is the same, but the molecular weight is different. Shown in Figure 1 as lines DSE and F. In yet another embodiment, the blend components are arranged in order of increasing molecular weight or comonomers. If arranged in order of increasing marmole content, comonomer content or fraction, respectively. The molecular weight is the same or higher.

As used herein, two or more blend components are defined by the MD of their blend. If W is as narrow as the MDW of each blend component, i.e. When the Mw/Mn value is less than about 3.0, preferably less than about 2.5, substantially the same It has a molecular weight of 1. Conversely, two or more blend components If Mw7Mn of the entire blend is relatively large compared to the MDW of each blend component, i.e., if the Mw/Mn value of the blend is greater than about 3.0. have different average molecular weights.

As used herein, two or more blend components constitute the entire blend. If CDB I is relatively small compared to the CDB I of each blend component, i.e. , if the overall blend CDB I is less than about 50%, different comonomer content have a rate. Conversely, two or more blend components If D is similarly narrow for each blend component, i.e. the CDBI of the resulting blend is 50% or more, they have substantially the same molar comonomer content. blur CD and MDW of the blend are based on the relative proportions of each blend component used in the blend. It is easy to see that it depends. Blend components are "same" for a given blend but not for another blend, e.g. Depending on the ratio of each blend component, blends where those components have a MDW of less than 3.0 or a blend with an MDW of 3.0 or higher. Ru. Similarly, blend components may contain ``different'' comonomers for a given blend. but not for different blends, e.g. for each blend. Depending on the proportion of the components, blends of CDBI with less than 50% of those components may be used. or a blend of 50% or more CDBI. Ru.

Figure 4 graphically shows the molecular weight and composition distribution of the bimodal blend of the present invention. . From this MDW/CD diagram, the comonomer content on each side of the blend components is different. However, it can be seen that the molecular weights of each blend component are almost the same.

The comonomer content of ethylene copolymer is the amount of comonomer fed to the polymerization reactor. It can be changed by adjusting. Comonomer fed to reactor Increasing the amount will increase the amount of comonomer incorporated into the resulting copolymer. Dew. The comonomer content of the produced copolymer can also be measured by NMR spectroscopy. It can be measured in correlation with density. Generally, incorporated into the resulting polymer. As the comonomer content incorporated increases, the density of the polymer decreases.

The blend in FIG. 4 corresponds to line B in FIG. On the contrary, in a typical conventional LLDPE A similar graph for this can be seen in FIG. 2 as well as line A in FIG. These figures are low It shows that the molecular weight fraction has a higher comonomer content than the high molecular weight fraction. this A relatively high comonomer content, as seen in conventional LLDPEs such as Molecular weight molecules have poor surface properties, high blocking and tackiness, and stickiness. raw materials, high levels of extractables, and fouling of polymerization plants. Sometimes. In the present invention, curves BSC, DSE and F as shown in FIG. A heat sheet comprising ethylene copolymers or ethylene copolymer blends of various types By providing products that are based on Various properties improve.

As one specific example of the embodiment of curve B, M with a 1-butene content of 6.4 mol% -LLDI'E component of w80400 (Mw/M n=2.3; CD B I; 67%, MI=4. Odg/+in, density = 0.9042 g/cm’) and HDPE with a 1-butene content of 0.0 mol% and an Mw of 76,700 (Mw/Mn =2.8. CDB 400%, MX = 5, 0 dg/win, density = 0 , 9552 g/cnq) is a 50-50 blend with 210 g/ii1 It had a high tensile strength. Surprisingly, the first blend component and the second blend The tear strengths of the bond components were 1-11 g/+il and 48 g/mil, respectively. In contrast, this blend has improved tear strength. Additionally, these same ingredients The 25-75 blend has a higher elemental content of 227 g/i+il. It had high tear strength. Second Ll with lower tear strength, blend of DPE component Despite increasing the compounding ratio, the expected results from polyethylene produced using conventional technology Rather than the tear strength decreasing as shown in This result is extremely surprising and can be called a surprising result, as the Ru.

In another embodiment illustrated in FIG. 5 and line C in FIG. Fabrics with narrow compositional distributions and nearly identical comonomer content but different molecular weights By blending linear polyethylene components, multimode MDW can be created. can get. The MDW of such blends improves their melt processability and rheological properties. let it go up

For example, high throughput, high bubble stability, high shear sensitivity, as well as reduced withdrawal The above blend can be formulated to have vibrational properties. On the other hand, individual The optical, mechanical and surface properties of the blend components are typically for example, tear strength, modulus, yield strength Properties such as transparency, gloss, haze, heat sealability, and hot adhesion have been improved. On the other hand, blocking performance decreases. Additionally, such blends can be extracted with solvents. The proportion of functional polymer molecules is lower than in prior art copolymers with similar molecular weight distribution. do not have. The desired molecular weight and composition distributions can be achieved by combining several suitable ethylene copolymer components. may be obtained by manufacturing separately and blending these components, or These blend components can be polymerized simultaneously in the same reactor or in multiple reactors. It may be obtained by

The high molecular weight fraction with relatively low comonomer content contained in conventional LLDPE is During the next processing process, "row nucleated" or "shish cover" shish-ka-bab results in an anisotropic morphology known as the J-form. There are things that I do.

Such anisotropic morphology is due to the poor toughness of the product crystallized from the fluid melt. it is conceivable that. In the present invention, as shown in Blends B, C, DSE and F, Introducing polymer into the blend component and high molecular weight component with relatively low comonomer content Minimize anisotropy by providing bread with a low concentration of Can be done.

In another embodiment illustrated in FIG. 6 as well as the lines in FIG. It has a compositional distribution similar to that of fabrics, but contains components with different average molecular weights and average comonomer contents. I'm here. However, in contrast to conventional LLDPE as shown in line A in Figure 1 as well as in Figure 2, Generally, the blend of this embodiment contains a higher molecular weight fraction (or component) than a lower molecular weight fraction (or component). The fraction (or component) has a higher comonomer content. Such a distribution is, for example, , multiple linear polyethylene resins with narrow MDW and CD, which can be used to increase molecular weight. Blends that increase the comonomer content when arranged in the order of You can get it by doing this. Such a blend is also illustrated in line F in FIG. As mentioned above, it may contain two or more blend components having the same molecular weight. , in such cases, such blend components have an increase in their average comonomer content. It is included in the secondary hierarchy in the hierarchy. Also, the same comonomer content The presence of two or more blend components having such identical comonomer content also Blend components with a higher comonomer content and molecular weight than those of the blend components or Contains at least one blend component with low comonomer content and molecular weight. For example, as illustrated by line E in FIG. . In this embodiment, the blend preferably includes Blend formulations with higher molecular weight and lower comonomer content than other components It does not contain substantially any amount.

Such blends are similar to prior art blends and conventional L　LD　P　E resins ( In these, the comonomer content generally decreases with increasing molecular weight of the component or fraction. It has much better heat-sealing properties than other products. Conventional LLDPE resin The anisotropic “shield” caused by low concentrations of comonomers present in high molecular weight molecules Such The isotropy and toughness of films made from the blends are also improved. Furthermore, it takes The blend also has other desirable properties, such as traditional heat sealability. Compared to LLDPE resin, blocking properties are lower, friction coefficient is lower, and extraction is easier. I don't have enough minutes.

Preferred blends of the invention generally have a density of 0.88 to 0.94 g/c1 , melt index (MI) of 0.5 to 2.0 (according to ASTM D-1238) Ml).

In particular, some preferred blends incorporate two different ethylene copolymer components. Manufactured by The first component has a density of 0.88 to 0.92 g/cm3 and M It is a high molecular weight ethylene copolymer with l being 0.05 to 2. The second component has a density of 0.9 Low molecular weight ethylene copolymer with Ml of 1 to 0.96 g/cm' and 50 to 1000. be. Blend 50-70% by weight of the first component and 30-50% by weight of the second component. A blend with excellent heat sealability is obtained.

The linear polyethylene blend components of the present invention have a narrow ethylene content in both CD and MDW. Produced using a metallocentive catalyst system known to give polymers be able to. Ethylene used individually or as a blend in the present invention For the production of polymers, cyclopene using a combination of alumoxane cocatalyst and metallocene complex is used. Tagenylide catalyst systems or their reactants are suitable. Metallocene catalyst has the general formula (Cp), , M R, R'. In the formula, Cp is cyclopene is a tagenyl ring, M is a transition metal of Group 1 or Group VB, and R and R ' is hydrogen, a hydrocarbyl group or a hydrocarboxy group having 1 to 20 carbon atoms They were independently selected, m・1~3, n=0~3, n=0~3, n+m+ The sum of p is equal to the oxidation state of M. In the polymerization for producing the polymer component of the present invention, Various forms of metallocene-type catalyst systems can be used, and such catalyst systems include Gas phase polymerization, high pressure polymerization, slurry polymerization with monocatalyst system or heterogeneously supported catalyst Alternatively, the above catalyst and alumoxane promoter are placed on a carrier that is inert to polymerization in solution polymerization method. This includes those supported or reacted with a medium.

The cyclopentadienyl group of the above catalyst may be unsubstituted, hydrogen or hydrogen. It may be substituted with a drocarbyl group. Such hydrocarbyl groups contain carbon atoms. Alkyl, alkenyl, aryl, alkylaryl, ary with 1 to 20 children two carbon atoms of rualkyl group and similar groups, or cyclopentagenyl Includes those in which atoms are bonded to form a C4-C6 ring. Hydrocarbyl-based ingredients Examples include methyl, ethyl, propyl, butyl, amyl, isoamyl, and hexyl. Syl, isobutyl, heptyl, octyl, nonyl, decyl, cetyl, 2-ethyl Examples include hexyl and phenyl. Specific examples of halogen substituents include chlorine, odor This includes fluorine, fluorine, and iodine. Among these halogen atoms, chlorine is preferred. stomach. Specific examples of hydrocarboxy groups include methoxy, ethoxy, propoxy, but Includes oxy, amyloxy, etc.

Illustrative, non-limiting examples of metallocene catalysts useful in making the polymers of this invention include: , bis(cyclopentagenyl) titanium dimethyl, bis(cyclopentagenyl) ) titanium diphenyl, bis(cyclopentadienyl) zirconium dimethyl, bis Bis(cyclopentadienyl)zirconium diphenyl, bis(cyclopentadienyl) hafnium dimethyl, bis(cyclopentadienyl) hafnium diphenyl bis(cyclopentagenyl) titanium dineopentyl, bis(cyclopentagenyl) genyl) zirco, nium dineobentyl, bis(cyclopentagenyl) tita dibenzyl, bis(cyclopentadienyl) zirconium dibenzyl, bis( cyclopentagenyl) vanadium dimethyl; monoalkyl metallocenes, e.g. For example, bis(cyclopentadienyl) titanium methyl chloride, bis(cyclopentadienyl) titanium methyl chloride, phenyl) titanium ethyl chloride, bis(cyclopentagenyl) titanium phenyl salt Bis(cyclopentadienyl) zirconium methyl chloride, bis(cyclopentadienyl) pentagenyl) zirconium ethyl chloride, bis(cyclopentagenyl) di Ruconium phenyl chloride, bis(cyclopentadienyl) titanium methylpropylene Do, bis(cyclopentagenyl) titanium methyl iodide, bis(cyclopentagenyl) genyl) titanium ethyl bromide, bis(cyclopentagenyl) titanium phenyl Lupromide, bis(cyclopentagenyl) titanium phenyl iodide, bis(cyclopentagenyl) titanium phenyl iodide, clopentagenyl) zirconium methylbromide, bis(cyclopentagenyl) ) zirconium methyl iodide, bis(cyclopentagenyl) zirconium Methyl iodide, bis(cyclopentagenyl)zirconium ethyl bromide, Bis(cyclopentadienyl)zirconium ethyl iodide, bis(cyclopentadienyl) tajenyl) zirconium ethyl bromide, bis(cyclopentajenyl) zil Conium ethyl bromide, bis(cyclopentadienyl) zirconium ethyl bromide Uride, bis(cyclopentagenyl)zirconium ethyl iodide, bis(cyclopentadienyl)zirconium clopentagenyl) zirconium phenylbromide, bis(cyclopentagenyl) zirconium phenyl iodide, etc.; and trialkyl metallocenes, For example, cyclopentagenyl titanium trimethyl, cyclopentagenyl zirco triphenyl, cyclopentagenyl zirconium trineopentyl, cyclopentadienyl zirconium Clopentagenyl zirconium trimethyl, cyclopentagenyl hafnium triphenyl, cyclopentagenyl hafnium trineopentyl, and cyclo Includes pentagenyl hafnium trimethyl, etc.

Other metallocenes that may be usefully used in the preparation of the polymer components of the present invention include monocyclo Pentagenyl titanocenes, e.g. pentamethylcyclopentadienyl titanium trichloride, pentaethylcyclopentadienyl titanium trichloride, etc.; bis( pentamethylcyclopentadienyl) titanium diphenyl; formula bis(cyclopentagenyl); carbenes represented by (genyl) titanium/CH2 and their derivatives, such as bis (Cyclopentagenyl) T i = CH2・A I (CH3)3, (Cp 2T I CH2)2, C1)2Ti CH2CH(CH,)CH2,CI) 2T 1-CHCH2CH2 etc. (Cp is cyclopentagenyl ); Substituted bis(cyclopentadienyl)titanium(IV) compounds, e.g. (denyl) titanium diphenyl or dichloride, bis(methylcyclopentagenyl) ) titanium diphenyl or dihalide, etc.; dialkyl-, trialkyl-, Tetraalkyl- and pentaalkyl-cyclopentadienyl titanium compounds, e.g. For example, bis(1,2-dimethylcyclopentadienyl)titanium diphenyl or di-salt compound, bis(1,2-diethylcyclopentadienyl)titanium diphenyl or di Chlorides and other dihalogenated complexes, etc.; silicon, phosphine, amines or carbon cyclopentadiene compounds bridged with, e.g. dimethylsilyldicyclopene Tajenyl titanium diphenyl or dichloride, methylphosphine dicyclopentadi phenyl titanium diphenyl or dichloride, methylene dicyclopentadienyl titanium Included are diphenyl or dichloride and other dihalogenated complexes.

Zirconocene catalysts useful in the present invention further include bis(ethylcyclopentadiene). cyclopentadienyl) zirconium dimethyl, bis(cyclopentadienyl) zirconium dimethyl Chil, bis(cyclopentadienyl)zirconium methyl chloride, pentamethyl Cyclopentadienyl zirconium trichloride, pentaethyl cyclopentaje Nylzirconium trichloride, bis(pentamethylcyclopentadienyl)zyl Conium diphenyl, alkyl-substituted cyclopentadines, e.g. bis(ethyl) cyclopentagenyl) zirconium dimethyl, bis(β-phenylpropyl clopentagenyl) zirconium dimethyl, bis(methylcyclopentagenyl) ) zirconium dimethyl, bis(n-butyl-cyclopentadienyl)zirco dimethyl, bis(cyclohexylmethylcyclopentadienyl)zirconi Zirconium dimethyl, bis(n-octyl-cyclopentadienyl) zirconium dimethyl dialkyl and their alkyl halides and dihalogenated complexes; dialkyl- , trialkyl-, tetraalkyl- and pentaalkyl-cyclopentadiene such as bis(pentamethylcyclopentadienyl)zirconium dimethyl, Bis(1,2-dimethylcyclopentadienyl)zirconium dimethyl and this dihalogenated complexes; cyclopentadiene bridged with silicon, phosphorus and carbon compounds such as dimethylsilyl dicyclopentadienyl zirconium dimethyl or dihalide, methylene dicyclopentadienyl zirconium dimethyl or are dihalides, etc., and methylene dicyclopentadienyl ethylene bridges are Bis(tetrahydroindenyl)zirconium dimethyl or dihalide, and carbenes represented by the formula Cp2Zr=CHP(C6H1)2CH3 and these derivatives of compounds such as Cp2Zr CH2CH(CH3)CH2, etc. included.

Bis(cyclopentagenyl) hafnium dichloride, bis(cyclopentagenyl) ) vanadium dichloride and bis(cyclopentagenyl)vanadium dichloride etc. are mentioned as examples of other metallocenes.

Alumoxane is a polymeric aluminum compound with the general formula (R-AI-0 ), , and R(R-A 10-). It is represented by AlR2, but the former is a cyclic compound and the latter is a linear compound. In the above general formula, R is C, -C, alkyl radicals such as methyl, ethyl, propyl, butyl and pentyl. and y is an integer from 2 to about 20. Production of alumoxane (e.g. aluminum (from trimethyl and water) generally gives a mixture of linear and cyclic compounds.

Alumoxane can be obtained in various ways. The alumoxane is preferably Aluminum trialkyl (e.g. aluminum trimethyl) is combined with a suitable organic by contacting with water in a solvent (such as benzene or an aliphatic hydrocarbon). Manufactured by For example, aluminum alkyls are treated with water in the form of a humid solvent.

Alternatively, aluminum alkyls such as aluminum trimethyl can be hydrated with copper sulfate. It may also be brought into contact with salt hydrates such as

Alumoxane is preferred (as described in U.S. Pat. No. 4.665.208). Produced in the presence of ferrous sulfate hydrate as described in The disclosure of this U.S. patent is Incorporated herein by reference. This method uses alcohol dissolved in toluene etc. A dilute solution of trimethyl trimethyl is It consists of treatment with ferrous acid. Ferrous sulfate for aluminum trimethyl The ratio is preferably about 1 mole of ferrous sulfate to 6 to 7 moles of aluminum trimethyl. It is le.

The reaction can be confirmed by the evolution of methane.

The ratio of aluminum in the alumoxane to total metal in the metallocene is approximately 0.5: 1 to about 10,000:1, preferably about 5=1 to about 1,000:1.

To support the catalyst system for producing the copolymers and blend components of the present invention, Various inorganic oxide supports may be used. Polymerization is generally carried out over a temperature range of about 0 to 160°C. Although higher temperatures may be used. However, this temperature range It is not essential for the production of light copolymers and blend components. These copolymers and the blend components can be any technology that results in the above structure. It may be manufactured by Polymerization using the metallocene catalysts described above can be carried out at atmospheric pressure or reduced pressure. Overpressure conditions are used. For polymerization of ethylene polymers, based on monomer weight from about 1 ppm to about 5000 ppm+, most preferably from about 10 ppm to about It is generally preferred to use a concentration of the catalyst composition that is 300 ppm.

Slurry polymerization generally requires pressures exceeding atmospheric pressure and temperatures in the range of 40 to 110°C. degree is used. Slurry polymerization involves the production of solid particulate polymer in a liquid polymerization medium. A suspension is formed in which the liquid polymerization medium contains ethylene, comonomer, and often water. and the catalyst are added together with the catalyst. The liquid used as the polymerization medium can be an alkane or a cyclo It can be an alkane, or an aromatic like toluene, ethylbenzene or xylene. Group hydrocarbons may also be used. The medium used must be liquid under the polymerization conditions and It must also be relatively inert. Preferably use hexane or toluene do.

In a variant, the polymer components of the invention can also be synthesized by gas phase polymerization. Gas phase polymerization method Pressures above atmospheric pressure and temperatures in the range of 50°C to 120°C are used. gas phase weight agitation in a pressure vessel adapted to separate product particles from unreacted gases. It can be carried out in a stirred or fluidized catalyst bed and product particles. Particles at 50℃~ To maintain a temperature of 120°C, ethylene, comonomer, hydrogen and inert A diluent gas (such as nitrogen) may be introduced or recirculated at a constant temperature. water, acid Triethylaluminum as a scavenger for aluminum and other impurities may be added as appropriate. Polymer products are produced in such a way that the amount of product remaining in the reactor remains constant. It may be taken out continuously or semi-continuously at a dripping rate. Polymerizes and steals the catalyst After activation, the produced polymer can be recovered by suitable means. For commercial implementation In some cases, the polymer product can be recovered directly from the gas phase reactor and residual monomers removed with a nitrogen purge. Once separated from the catalyst, it can be used without further deactivation or removal treatment.

The resulting polymer is extruded into water to form pellets or pellets as known in the art. Cut into appropriate strips. As also known in the art, pigments, antioxidants agents and other additives may be added to the polymer.

The blends of the present invention contain the desired components in the desired proportions using conventional blending techniques. Blend using equipment (e.g. screw extruder, Banbury mixer, etc.) Manufactured by or alternatively, e.g. 2 in one reactor. using one or more types of catalyst or two or more catalysts in series or parallel By using one type of catalyst in the reactor, blend components can be directly processed without isolation. Blends may also be made by polymerization. Such blends may contain, for example, antioxidants, purple Known in the art, such as external light stabilizers, pigments, fillers, slip agents, blocking agents, etc. It may be blended with various conventional additives. Preferably, the blend is LLDP have a significant negative impact on the properties desired to be improved by blending the E-resin. Contains no blending ingredients that would cause

Both CD and MDW narrow ethylene copolymers can be synthesized as described above. Wear. These ethylene copolymers are particularly suitable for products with desirable heat-sealing properties. It can be used in the production of In particular, these ethylene copolymers are particularly desirable. It can be processed into films with new heat sealability and other properties. ethylene Copolymers have a higher average molecular weight than the other blend components. At the same time, it is substantially free of blending components with low average comonomer content. independently selected.

Blends with narrow CD and MDW mean that the CDBI of the blend is 50% or more. Two or more types of ethylene selected so that MDW (Mw/Mn)≦3 made by blending copolymers. CD is narrow and MDW is wide. The blend is selected such that CDB I of the blend is 50% or more and MDW > 3. It is made by blending two or more ethylene copolymers.

Blends with a wide CD (narrow MDW) have a CDB I of less than 50% in the blend. Blend of two or more ethylene copolymers selected so that W≦3 made by doing. In addition, copolymers with narrow CD and MDW Can be blended with polymers with less than 50% I and MDW>3.

Such ethylene copolymers can be used in any environment where heat sealing is important or required. May be used for manufacturing products.

For example, such ethylene copolymers and blends thereof are commonly known in the art. Films that are processed into bags and pouches using known heat sealing technology. Can be used for manufacturing. Heat-sealable film is used as a packaging material as a sealing material. It can also be used for For example, such a film can be placed over the opening of a container and then heated. Also, make sure it is firmly attached to the container. Such technology is suitable for perishable products such as food products. Products in paper, plastic, glass, ceramic or metal containers It can also be used for sealing. This technology presents consumer goods with attractive sales displays. It can also be used to package plastic items and secure consumer goods for transportation. Wear.

These products are manufactured from ethylene copolymers and blends thereof. It is. The product may contain other materials, especially those used for heat sealing. Other materials may be included in product parts that are not included.

In the product part used for heat sealing, the phrase "manufactured from" Mawashi means "containing". In a further preferred embodiment, , these products in whole or in part contain substantially the ethylene copolymer of the present invention or It may be assembled to consist only of a blend thereof. In other words, these The heat-sealed portion of the product consists essentially of the ethylene copolymers of the present invention and their It may be composed only of a blend.

The ethylene copolymers of the present invention are formed into films by methods known in the art. . For example, it is possible to extrude the above polymer through a flat die in a molten state and cool it. stomach.

Alternatively, the polymer can be extruded in the molten state through an annular die and air blown into it. It may be mixed, cooled, and formed into a tubular film. Tubular film is axial It can also be cut in the opposite direction to make a flat film. The films of the present invention are stretched It is not necessary to do so, or -axial stretching or biaxial stretching may be performed.

Films of the present invention may be single layer or multilayer films. multilayer film , one or more layers made from ethylene copolymers and blends thereof. It may be composed of. Such films may be made of polyethylene or polyester, for example. or another polymer such as EVOH, metal foil, paper, etc. may have additional layers.

Multilayer films can be manufactured by methods known in the art.

If all layers are polymers, add these polymers to the coextrusion feedblock. coextrusion through a block and die assembly to produce two or more products of different compositions. It is also possible to obtain a film with an adhesive layer. Multilayer film is made from polymer It is also possible to use an extrusion coating method in which the hot molten polymer is brought into contact with the substrate while being discharged. Obtainable. For example, while extruding an ethylene copolymer film through a die, The ethylene copolymer film presses the already formed polypropylene film. Cover up. In the extrusion coating method, the base material to which the ethylene copolymer heat seal layer is applied is Woven or knitted from natural or synthetic fibers or yarns (e.g. textiles) , or if the substrate is a non-polymeric material such as glass, ceramic, paper or metal. This is particularly useful in cases where

A multilayer film is a combination of two or more monolayer films produced as described above. They can also be manufactured together.

For example, a polypropylene base film can be converted into an ethylene copolymer heat seal film. Combined with the strength of polypropylene, the heat shield of ethylene copolymer film is It is also possible to obtain a two-layer film that has both elasticity and elasticity.

The above two layers constituting the film produced in this way can be assembled using an adhesive or Alternatively, they may be joined by applying heat or pressure.

A good heat-sealable polymer has several important properties. one important characteristic is the heat sealing start temperature. This occurs when the polymer is heated to that temperature. It is the temperature at which effective bonding with itself under pressure occurs for the first time. therefore, When the heat seal temperature exceeds this heat seal initiation temperature, a significant and measurable Provides sealing strength. In commercial heat sealing equipment, the heat seal initiation temperature is A relatively low value is desirable. If the heat seal starting temperature is low, it will be difficult to make a seal. Speeding up the operation of the above equipment as it is not necessary to heat the polymer to very high temperatures. Can be done. In addition, the cooling time of the seal to obtain appropriate strength is fast.

Another important property is seal strength plateau temperature (seal strength p (lateau on-set temperature). This is polymerization heating the body to that temperature is achievable for that particular material to be sealed. This is the temperature at which a seal with maximum strength (after cooling) is obtained for the first time. heatshi By gradually increasing the heat sealing temperature at a temperature higher than the heat sealing start temperature, , the strength of the seal obtained gradually increases. The heat seal temperature reaches a certain point Until then, the seal strength continues to increase as the heat seal temperature increases; At temperatures above, the seal strength no longer increases. This temperature increases the seal strength. This is the temperature reached by Rato. More importantly, the temperature at which the seal strength plateau is reached is It cannot be destroyed by peeling alone or by peeling/tearing, and cannot be destroyed by tearing. is the lowest heat sealing temperature that will give a heat seal that can only be broken by It is normal to If the peeling operation destroys the heat seal, the two sealing surfaces separates neatly. If the seal is destroyed in this way, the seal strength will be reduced. Ino is normal. If the heat seal is destroyed by peeling/tearing, the two seals The roll surface undergoes considerable stretching or elongation during the separation operation. Heat seal with tear operation is destroyed, the failure does not occur in the seal itself, but in the material surrounding the seal. . Maximum seal strength is reached when failure occurs only by a tearing operation. sticker The seal failure pattern changes at the temperature at which the strength plateau is reached, so seal failure The seal strength plateau temperature can be determined from the appearance of the seal. heat seal For the same reasons mentioned for the starting temperature, the temperature at which the seal strength plateau is reached should be low. For example, commercial sealing equipment can be operated at high speeds.

The third important property is the sealing window, which is the allowable temperature range for seal creation. (sealing working temperature frame).

The sealing window should be kept at a working temperature such that the seal strength remains virtually constant. This is within the acceptable range. The lower temperature limit of this range is the plateau reaching temperature; The upper temperature limit is the temperature at which the seal strength begins to decrease or the polymer begins to deteriorate. Ru. Commercial sealing equipment often maintains a constant temperature throughout the commercial sealing operation. Since it is difficult or impossible to maintain It is now easier to ensure that all heat seals produced are of sufficient strength. Ru.

Heat-sealed products are made by sealing at least two parts of the product into smaller parts of the product. can be produced by crimping at a temperature sufficient to soften at least one Wear.

The part of the product that is softened by heat in this way is made of ethylene having a CDBI of 50% or more. Containing a copolymer or more than one such ethylene copolymer as a blend component Made from a polymer blend of Heat pressed to form a heat seal Only one of the product parts contained in the product is made from an ethylene copolymer or ethylene copolymer blend. It would be sufficient if the product was manufactured, but if the product parts directly involved in heat sealing Preferably all are made from ethylene copolymers or blends thereof. . Other parts of such products may be made of other materials.

The heat sealing temperature should be sufficient to soften the copolymer; By doing so, the copolymer is exposed to the material to which it is being sealed. Let it adhere. The heat sealing temperature is a temperature near the melting point of the above copolymer or Temperatures may be increased to higher temperatures, but at such high temperatures, seal contact may occur. It is necessary to shorten the time.

The seal heats one or both of the product parts to the required temperature and Crimp these product parts long enough for fusion to occur at least partially, and then manufactured by cooling the seal at required for joining these parts. The pressure applied depends on the shape of the product, the thickness of the seal layer, the composition of the seal layer, and the pressure used to create the seal. depends on the temperature. Heat-sealed products manufactured in this way have a main body and a sealing member fixed to a container, the sealing member being fixed to a narrow assembly. Ethylene copolymers with a compositional distribution as well as a plurality of such ethylene copolymer components A container comprising a sealing layer comprising one of the group consisting of a blend. It's okay.

The body can be made of several different materials (paper, plastic, glass, ceramic, etc.) as mentioned above. It may be made of wood, metal, fabric, etc.). The body is resistant to liquids and/or gases. It may be made of a wall that is impermeable to liquids and/or gases, or a wall that is permeable to liquids and/or gases. It may be made of the body. The body also allows small items to pass through the walls of its body. It may be assembled to have one or more entrances and exits that allow access to the container, or Allows consumers to view the product stored in the container without removing the product It can be assembled into

FIG. 13 shows a container body 132 and a sealing member 134 (these are the sealed chamber 13 FIG. Seal containers should be heat shielded. may have a flange 138 to provide additional surface area for making a wall. .

For commercial applications, after filling the open chamber 136 with the product to be packaged, the sealing member 134 against flange 138. The sealing member 134 and the flap before contact. 138 or both may be preheated, or any of the above may be applied after contact. Either or both may be heated.

In any case, at a temperature sufficient to soften the seal member 134, Press material 134 against flange 138. Temperature sufficient to form a heat seal After pressing the seal member 134 against the flange 138 under high temperature and pressure, Remove pressure and allow sealing surfaces to cool. The resulting product is placed in chamber 136. A sealed container containing consumer goods.

As mentioned above, the seal member is made of the ethylene copolymer of the present invention or a blend thereof. Alternatively, the sealing member may be a multilayer film. sticker When the member is made of two or more materials, the ethylene copolymer of the present invention or The blends need only be applied to the surfaces to be heat sealed. For example, The roll member can also be made as shown in FIG. Here, Fig. 14 shows the double-layer film. FIG. The sealing member 144 includes a base material layer 143 and a heat sealing layer 145. So that the present invention, including its typical advantages, may be better understood , Reference examples of practical tests in which the present invention was actually carried out are listed below, and the present invention is explained below. Unexpected and surprising heat-sealing properties of light copolymers and their blends explained However, these references do not limit the scope of the invention.

Example I An ethylene copolymer was produced using a conventional technique and was designated as Sample A. Sample A is as described below. It was produced in a fluidized bed gas phase reactor using a titanium-based transition metal catalyst. Gas phase reactions are reaction temperature 83°C, ethylene pressure 130 psia, hydrogen/ethylene molar ratio 0.055 6, a butene/ethylene molar ratio of 0.0263 and a residence time of 2.4 hours. Living The formed polymer incorporated 4.82 mole percent butene as a comonomer.

A second known copolymer was prepared in a liquid slurry phase reaction and designated Sample B. of sample B The slurry phase reaction temperature used in the production was 83°C, and the ethylene pressure in the reactor was 130 ps. ia, the hydrogen/ethylene molar ratio in the reactor is 0.0556, and the residence time is 2.4 It was time. The resulting polymer incorporated 3.2 mol% butene as a comonomer. It was The prior art transition metal catalyst described above is disclosed in U.S. Pat. (the disclosure of which is incorporated herein by reference) Manufactured along. After calcining silica at 600°C, isopentane was added at 25°C. treated with triethylaluminum in a mixture of Next, add magnesium dichloride to , trichloride in the presence of aluminum trichloride and tetrahydrofuran (THF) solvent Reacted with titanium. The obtained reaction product was treated as described above in THF solvent at 50°C. silica prepared as described above. The resulting product was dissolved in isopentane at 50°C. treated with a mixture of diethylaluminum chloride and tri-n-hexylaluminum In this way, a catalyst used in the production of Sample B was obtained.

The physical properties of the resulting polymer are shown in Table I below. Melt index (MI) was measured according to ASTM D-1238, and 2. It is the number of grams of polymer extruded in 10 minutes under a load of 16 kg.

Tear resistance (TR) is determined according to ASTM D-1922 (PL-007). Measured using the Dolph pendulum method. Films behave differently in different directions. The tear resistance is measured in (kg/cm) in the machine direction (MD) and in the transverse direction (TD). I kept it. Intrinsic tear resistance (IT) was measured according to ASTM 922.

Drop impact resistance (DIR) is determined by ASTM D-1709-75 Method A (PL-0 It was measured by the falling spear method according to 02). Falling spear impact resistance is in (g++/a+il) unit. I met.

Haze is measured according to ASTM D-1003-61 Procedure A, and gloss is measured according to ASTM D-1003-61 Procedure A. Measured according to MD-2457-70 and ASTD-523-80. Cloudiness and Both gloss and gloss were expressed as percentages (%). Haze is different from gloss.

Glossiness is the luster of a film as seen by reflected light. The haze of the film is the transparency of the film. There is a reciprocal relationship with degree.

Hexane extract (HE) is 21 CF R (1,77, 1520 (d) (3) Food and Drug Class (FDA) as described in (it)) Measured in accordance with the procedures established by the Administration, and expressed as a percentage (%). I met.

=Ro 1　°　“-11-11-“ Yo81　　゛″′～′～−−″″″～°°１・　　　　　　　　　　　　　　　　,,, Yuyue, °・　 “%　套o1；・certain：：；；：j：　″″−i-i套I Wings Foothills Tomi Anal ll00 Takeshi 1 <“-eJMゞu’s cc+ +-c+o e+’+ c3 example■ A silica-supported transition metal catalyst according to the present invention was produced as follows. High surface area silicone About 100 g of mosquito (Davison 952) was heated at 800°C for about 5 hours under a stream of dry nitrogen. It was heated to dehydrate.

250 (1+l) round bottom flask equipped with a magnetic stirrer at 25 °C under nitrogen atmosphere. The above dry silica was put into 500 ml of dry toluene to form a slurry. After that The silica slurry was mixed with methylalumoxane 2 in toluene with constant stirring. 50ml (1.03mol/liter of aluminum was added dropwise over about 15 minutes. Stirring was continued for an additional 30 minutes while maintaining the temperature at 25°C. This alumoxane Bis(n-butylcyclopentadienyl)zirconia was added to the treated silica slurry. A toluene solution containing 2.00 g of umnichloride was added dropwise over about 15 minutes. drop The slurry temperature was maintained at 65°C during the lowering and for 0.5 hours thereafter. Continue stirring constantly. Afterwards, the toluene was decanted to recover the solids, and the solids were collected for several hours. It was vacuum dried for a while. Analysis of the catalyst revealed that it contained 4.5% by weight of alkali. zirconium and 0.63% by weight of zirconium.

The catalyst prepared by the above method was used in a gas phase reaction under the conditions shown in Table H. Each weight During the synthesis reaction, the indicated amount of ethylene mixed with nitrogen is added to the reactor along with the indicated amount of hydrogen. added to. The reaction time required to produce each polymer was about 2 hours to several hours.

The reaction temperature was maintained at the temperature shown in Table H, and the indicated amount of comonomer was added at the start of the reaction. added. After each reaction, the polymer particles were separated from the rest of the reaction mixture.

The molecular weight and density obtained for each blend component are shown in Table ■, and the blend Table 1 shows the properties of the

Sample A and Sample B described in Example I have a molecular weight as shown by line A in Figure 1. have a related comonomer distribution. Sample 1 has a narrow CD and a wide MDW; It is manufactured to contain a large amount of high molecular weight components. Things about sample 1 The relationship between mer distribution and molecular weight is along line C in FIG.

Sample 2 has a wide CD, a wide MDW, and a small amount of high molecular weight low density components. It is a blend of sea urchin.

The distribution plot for sample 2 follows the lines in FIG.

Sample 3 has a narrow CD and a wide MDW, and has been blended to contain a large amount of high molecular weight components. This is the result of the The distribution curve for sample 3 follows line C in FIG.

Sample 4 has a narrow CD, a wide MDW, and contains a small amount of high molecular weight components. So The comonomer distribution of is along line C in FIG.

Sample 5 has a wide composition distribution and wide molecular weight distribution, and contains a small amount of high molecular weight and high density components. It includes. This sample is a blend that mimics prior art polymers. . The distribution for sample 5 is along line A in FIG.

Sample 6 has a wide CD and a wide MDW, and contains a large amount of high molecular weight and low density components. Ru. The distribution for sample 6 follows the line in FIG.

Sample 7 has a wide CD and a narrow MDW, and contains equal amounts of high-density variations and low-density components. I'm here. The distribution for sample 7 is along line B in FIG.

Sample 8 has a narrow CD and a narrow MDW, a molecular weight of 5oooo, and a density of 0.9049. It consists of a single copolymer component.

Sample 9 is a single copolymer with a narrow CD and a narrow MDW. Sample 9 is approximately It has a high molecular weight of 96,500 and a density of 0.9104.

Sample 10 is also a single copolymer component with a narrow CD and a narrow MDW. Sample 10 is It has a molecular weight of 84,300 and a density of 0.9147.

Example ■ Films made from Samples A and B were placed on a 1-inch Egan blown film line ( Egan Blown Film Line) (Tower Flight Model) It was manufactured at a blow ratio of 4:1. Each film produced was about 2, Oml. (50 microns). Blends of sample numbers 1 to 8 each had Pf Large twin screw set compounder of leiderer ZSK-57 model homogenized using a mixing extruder. The fibres of each resin blended in this way 1 inch Ki l 1 ion mini cast film line (I[1ll ion Mint Ca5t Film Line) K L B 100 model The thickness is 1.5-2. (Jail (37.5-50 micron) It was Lumu. Samples 9 and 10 each contain only one type of polymer component, so they are blank. No lending was required. The films of samples 9 and 10 were 2 inches Ca 1lin FilmCast Line ) manufactured above.

From these films, a laboratory-scale heatshield of the Teller EB model was developed. I made a heat seal on a roller. The pressure retention time was approximately 1 second, and it was used to create the seal. The sealing pressure was 50 N/cm2. Blown film and casting film For films, the seal on the film is made in the transverse direction and The building is made of Myler film and does not touch the heat seal film directly. I did it like that. Mylar film is very stable at normal heat sealing temperatures. and can be easily removed from the heat seal polymer after seal creation. child The seals were aged for 24 hours before their strength testing.

For strength testing, seal samples were cut to 1 inch (2.54 cm) wide and installed. Using a Ron testing machine, strain rate of 508 mm/min and 2 inch (5,08 cm Strength tests were conducted with a crosshead spacing of m). Place both free ends of the sample into the crosshead. Fix it and pull the crosshead apart at the above strain rate until the seal breaks. . Measure the peak load at the time of seal failure and divide that peak load by the thickness of the sample. Calculate the seal strength.

The heat sealing start temperature was determined by measuring the sealing strength of each sample sealed at various temperatures. By extrapolating the plot of temperature versus seal strength, Determined by measuring low temperature. Using this same plot, 2 N70m The seal strength can be determined by the temperature at which it occurs. This plot also It can also be used to set the toe temperature as well as the seal temperature window. Conventional These measurements were made for the technology sealing film and the invention sealing film. The values of properties are shown in Table ■.

Qualitatively ranking the performance of each sample shows that It can be seen that the sheet seal is superior to that of the prior art. Prior art polymerization The body is represented by samples A and B, and is ranked at the top of the hierarchy shown in Table 3. this These are the least desirable among the samples ranked in Table ■. of this table The sample on the bottom shows the heat sealing temperature required to obtain the seal strength at the indicated level. It is the lowest and therefore the most desirable. Sample 5 is the conventional technology It is a blend that mimics the composition distribution of polymers, and as shown in Table ■, the sample The properties of No. 5 are almost as poor as those of prior art polymers.

2. Although the seal strength of N70m is an arbitrarily chosen value, it is commercially useful. This is an indicator of the minimum temperature required to provide a good heat seal. Shown in Table ■ and Table ■ Accordingly, in the present invention, the heat sealing temperature is 95°C or lower, 90°C or lower, and even 85°C. A seal having a seal strength of 2N/C1 can also be obtained below. Prior art sample A and B, and Sample 5, which was blended in imitation of the prior art, had a sheet of 2N70m. Heat sealing temperatures higher than 95°C are required to produce seals with high seal strength. be. A temperature below 95° C. is sufficient for all blends of the invention. these temperatures Although the difference in absolute value is a few degrees Celsius, the temperature required for sealing with conventional polymers is It can be said that it is much lower than the average temperature. Such a slight decrease in the absolute value of the heat seal temperature However, significant improvements are expected in commercial heat-sealing processes. As mentioned above, The lower the sealing temperature, the faster the sealing process and the heat sealing equipment. It becomes possible to increase productivity per unit.

Table■ A 105 109 126 44 B 93 96 123 47 1 86 g8 120 50 3 80 84.5 115 55 9 82 84.5 112 58 10 91 91.5 113 57 Table■ Sample sequence temperature for the temperature required for the title seal strength Seal start 2 N/Cal Highest plateau reached A A 5 Minimum 3 9 9 All the resins of the present invention show improvement in heat sealing properties, but the data in Tables ■ and ■ As can be seen from the data, samples 1.3.6.7.8 and 9 in particular are polymers of the prior art. It's much better than. These are 2N/c at a heat sealing temperature of 90℃ or less. Produces a trr strength seal. In samples 3 and 9, the sheet of such strength was obtained at temperatures below 85°C. can be obtained. The heat sealing table of the present invention made from these specifically mentioned polymers To further illustrate the transmissibility, there are graphs shown in FIGS. 7 to 12.

Figure 7 shows the sealing curves of two prior art polymers (Sample A and Sample B). be.

These graphs show the heat shield measured in N/cm versus the temperature at which the seal was made. It represents the heat seal strength of the roll.

For comparison, the curves of sample A are shown in all of FIGS. 7 to 11.

Figure 8 shows the curves of samples 1.2 and 3, and shows the curves of samples 1.2 and 3 using the conventional technique. This is a graphical representation of the advantages of this technique. The curve of the inventive sample is lower Starting at a low temperature and using narrow CD<MDW polymers or blends thereof. This shows that a low starting temperature can be obtained by These polymerizations of the present invention The strength of the seal made with Polymer A is higher than that of the prior art polymer A at the same heat sealing temperature. It's also expensive. For example, in Figure 8, samples 1.2 and 1 at a seal temperature of 100°C. The seal strengths of Samples and 3 are significantly higher than those of the prior art polymer (Sample A).

For example, the seal strength of sample A at 100℃ is less than IN/c- from this figure. However, on the other hand, the seal strength of sample 3 exceeds 6 N7 cm. . This figure shows that the sealing strength of the film of the present invention is significantly higher at a relatively low sealing temperature. It shows that it is improving.

FIG. 9 compares samples 4.5 and 6 with sample A. This figure also Sample 5, which is a blend that mimics the prior art polymer, is substantially the same as the prior art polymer. It shows that they have the same seal curve. Compared to these, samples 4 and 6 have beneficial properties as described herein. That is, samples 4 and 6 has a higher sealing temperature at the same sealing temperature than the prior art polymer represented by the sample. It has strong strength. For example, at 100°C, the seal strength of sample 6 is 4N7c The seal strength of sample A is less than 7 cm, whereas the seal strength of sample A is less than 7 cm.

Figure 10 illustrates the advantages of Samples 7 and 8 over prior art polymers.

This figure shows that Samples 7 and 8 exhibit the same desirable properties described herein. It shows. In other words, the seal initiation temperature is low and the seal strength at low temperatures is low. It's height. At a sealing temperature of 100°C, the polymers of the present invention also exhibits significantly higher seal strength. The resin of the present invention has a sealing strength of 4N/CIo or more , whereas the seal strength of prior art polymers is less than 7 cm .

Figure 11 shows a comparison of seal strength data for samples 9 and 10 with sample A of the prior art. It is. This figure also shows samples 9 and 10 at a sealing temperature of 100°C. Similar advantages are clearly observed, including much higher seal strength. Sample 9 and 10 have a seal strength of approximately 6 N/ci+ or more at 100°C, whereas The sealing strength of the technology polymer is less than 1N7cm.

Figure 12 compares the seal strength data of samples 1.3 and 9 with the prior art sample B. It is something. This plot also shows the advantages of the heat sealing of the present invention over the prior art ( That is, low heat sealing start temperature and sealing at a specified heat sealing temperature. strength).

These drawings show the commercial advantages to be gained from the use of the heat sealing products of the present invention. It is clear that The product of the present invention can be used at temperatures below 120℃, below 110℃ or below 100℃. The seal created in this way has sufficient It is also possible to ensure strong strength. In comparison, prior art polymers at 100°C It is not possible to obtain a seal with sufficient strength even when sealing at temperatures of 10℃ or even 120℃ or higher. Can not. Therefore, commercial It becomes possible to use the material of the invention in lines. The working temperature of 100℃ is , significantly lower than normal commercial sealing operating temperatures.

Using a sealing temperature such as 100°C can significantly increase heat sealing speeds. Therefore, the heat sealing material of the present invention can be used to produce heat sealing devices. height can be increased considerably. It was used in conventional sealing work. Even at such high heat sealing temperatures, the present invention offers the advantage of speeding up the sealing process. do. Due to the nature of the copolymers or copolymer blends of the present invention, heat sealing operations are possible. This allows you to create more seals with your existing heat sealing equipment. can be done.

Although the invention has been described with reference to specific embodiments thereof, there is no specific description herein. It will be readily understood by those skilled in the art that various modifications may be made to the present invention without further elaboration. It will be. For example, the catalyst systems described above have narrow molecular weight distributions and narrow composition distributions. alumoxane and/or ions as cocatalysts to produce copolymers with It contains various transition metal metallocenes activated with a sex activator. There may be. Therefore, in defining the true technical scope of the present invention, it is necessary to refer to the attached claims. Reference should only be made to the scope of the request.

Seal strength vs. temperature Seal temperature (℃) Seal strength vs. temperature 70 80 90 ioo 110 120 130140150160170 180 seal strength vs. temperature 70 80 90 100110 120 1301401501601701 B0 seal strength vs. temperature Seal strength vs. temperature 70 80 90 100110 120 1301401501601701 B.

Seal strength vs. temperature PCT/lls 92105924 international search report Continuation of front page (72) Inventor Touldell, Barry Collin United States of America, Texas 7 7059, Hyuston, Island Hills 4123 (72) Inventor Pan ・Del Sanden, Dirk Germain France Belgium, B-1820 Perk, Hogestrad 1D

Claims (1)

[Claims] 1. at a temperature sufficient to soften at least one of the first and second product parts. The product has a sealing area formed by crimping the first and second product parts. At least the first part is made of ethylene copolymer or ethylene copolymer block. 50% or more of the above blend or individual copolymer selected to have a composition distribution breadth index (CDBI) of The above part of the fruit can be sealed by contact at a sealing initiation temperature of less than 93°C. products to do. 2. The product of claim 1, wherein at least the first portion comprises a film. optionally said second portion is a polymer other than said copolymer or copolymer blend; characterized by comprising a similar film or layer of metal foil, paper or textile products. 3. The product according to claim 1 or claim 2, wherein the product comprises (i) a multilayer film. or (ii) the form of a sealed container, and the sealed container is (a) a main body. (optionally made of molded polyolefin) and (b) said first product part. The constituent sealing member has or includes a sealing layer that seals the main body. The sealing member may optionally include the above-mentioned sealing member. further comprising, or optionally at least, a supporting substrate adhered to the sealing layer. A product characterized in that it is a film consisting of two layers. 4. The product according to any one of claims 1 to 3, wherein the CDBI is 7. A product characterized by having a content of 0% or more. 5. A product according to any one of claims 1 to 4, comprising the blend or characterized in that each copolymer has a comonomer content of 0.01 to 17 mol% products. 6. A product according to any one of claims 1 to 5, comprising the blend or A product characterized in that each copolymer has a molecular weight distribution of 2.5 or less. 7. A product according to any one of claims 1 to 6, comprising the blend or Each copolymer is 0.875 to 0.96 g/cm3, preferably 0.89 to 0.93 density of g/cm3 and 10000-1000000, preferably 4000-2 A product characterized in that it has a weight average molecular weight of 00,000. 8. A product according to any one of claims 1 to 7, wherein the polymer blend The polyethylene component has a higher average molecular weight than the other polyethylene components in the blend, while at the same time It is characterized by being substantially free of blend components with low uniform comonomer content. Products with characteristics. 9. A product according to any one of claims 1 to 8, wherein the polymer blend The (1) Ethyl alcohols with substantially the same average molecular weight but different average comonomer contents Ren copolymer component, or (2) Ethyl alcohols with substantially the same average comonomer content but different average molecular weights Ren copolymer components, or (3) different average molecular weights and comonomer contents. If the components are arranged in order of increasing average molecular weight, the comonomer content will be as follows: an ethylene copolymer component such that the ethylene copolymer component increases (4) Combination of these A product characterized by containing. 10. A product according to any one of claims 1 to 8, wherein the polymer block Lends have a broad molecular weight distribution and optionally a narrow composition distribution. Products featuring: 11. The product according to any one of claims 1 to 10, wherein the polymer The blend is 0.88 to 0.94 g/cm3, preferably 0.90 to 0.92 g /cm3 and melt index (MI) of 0.5 to 20, and preferred or having a weight average molecular weight of 40,000 to 200,000. Goods. 12. 12. The product of claim 11, wherein the polymer blend has a density of 0.88 to 50-70% by weight of high molecular weight components with MI 0.05-2 at 0.92 g/cm3, and Low molecular weight component 30~ with density 0.91~0.96g/cm3 and MI50~1000 A product characterized in that it contains 50% by weight. 13. at a temperature sufficient to soften at least one of the first and second product parts. A method of creating a heat seal by crimping the first and second product parts above. , at least one of the above product parts has a composition distribution breadth index (CDBI) of 50% or more. or a blend of multiple such ethylene copolymers. and the heat seal has a sealing start temperature of less than 93 ° C. A method characterized by: 14. Ethylene copolymer having a composition distribution breadth index (CDBI) of 50% or more or A blend comprising two or more such ethylene copolymers is also used in the sealing area. A method for use as a sealing part in a product having a first part and a second part, A method characterized in that the sealing operation is started at a temperature below 93°C. 15. The product or method or method of use according to any one of claims 1 to 14 and the sealing start temperature is 80°C or higher and lower than 93°C. product or method or method of use. 16. The product or method or method of use according to any one of claims 1 to 15 and the seal reaches a plateau temperature in the range of 110°C or more and less than 123°C. A product or method or method of use characterized by: