阅读说明：本技术 包含无定形丙烯-乙烯共聚物和丙烯聚合物的粘合剂组合物 (Adhesive compositions comprising amorphous propylene-ethylene copolymers and propylene polymers ) 是由 T.R.卡瓦诺 M.C.屈珀斯 T.H.奎因 于 2018-06-08 设计创作，主要内容包括：在本文中描述了无定形丙烯-乙烯共聚物,其可以包含大量乙烯并表现出合意的软化点与针入度。在这些丙烯-乙烯共聚物中软化点和针入度的合意的组合使它们具有宽操作窗口。由于它们的宽操作窗口,该丙烯-乙烯共聚物可用于多种应用和产品,包括热熔性粘合剂。(Amorphous propylene-ethylene copolymers are described herein that can contain large amounts of ethylene and exhibit desirable softening points and strikethrough. The desirable combination of softening point and penetration in these propylene-ethylene copolymers makes them have a wide operating window. Due to their wide operating window, the propylene-ethylene copolymers are useful in a variety of applications and products, including hot melt adhesives.)

1. An adhesive comprising at least one propylene-ethylene copolymer and at least one high propylene content polymer, wherein the propylene-ethylene copolymer comprises at least 10 wt.% ethylene and has a softening point of at least 99 ℃.

2. The adhesive of claim 1 wherein the high propylene content polymer is selected from the group consisting of propylene homopolymers; metallocene-catalyzed polypropylene; propylene-ethylene copolymers; metallocene-catalyzed propylene-ethylene copolymers; propene and straight-chain or branched C₄To C₂₀Copolymers of olefins; propene and straight-chain or branched C₄To C₂₀Metallocene-catalyzed copolymers of olefins; propylene, ethylene and C₄To C₂₀Terpolymers of olefins; a propylene wax; a terpolymer formed from ethylene, propylene, and a diene (EPDM), or a combination thereof.

3. The adhesive of claim 1 wherein the propylene-ethylene copolymer comprises from 12 to 40 weight percent ethylene.

4. The adhesive of claim 1 wherein the propylene-ethylene copolymer has a softening point of 105 to 145 ℃.

5. The adhesive of claim 1, wherein the propylene-ethylene copolymer has a penetration of from 8 to 75 dmm, measured according to ASTM D5.

6. The adhesive of claim 1, wherein the propylene-ethylene copolymer has a crystallinity of less than 30% as determined using DSC according to ASTM E794-85 and a number average molecular weight (Mn) of less than 25,000 as determined by gel permeation chromatography.

7. The adhesive of claim 1 wherein the propylene-ethylene copolymer has a brookfield viscosity at 190 ℃ of less than 30,000 cps measured according to ASTM D3236.

8. The adhesive of claim 1, wherein the propylene-ethylene copolymer exhibits a glass transition temperature (Tg) of-60 to 20 ℃.

9. The adhesive of claim 1, wherein the adhesive comprises:

(a) 5 to 95 weight percent of the propylene-ethylene copolymer;

(b) 10 to 90 weight percent of the high propylene content polymer;

(c) up to 70 wt% of at least one tackifier;

(d) up to 20 wt% of at least one processing oil; and

(e) not more than 20% by weight of at least one wax.

10. The adhesive of claim 1, wherein the adhesive comprises:

(a) 30 to 95 weight percent of the propylene-ethylene copolymer;

(b) 10 to 55 weight percent of the high propylene content polymer;

(c) up to 40 wt% of at least one tackifier;

(d) up to 20 wt% of at least one processing oil; and

(e) not more than 20% by weight of at least one wax.

11. The adhesive of claim 1 wherein the adhesive has a brookfield viscosity at 177 ℃ of 800-5000 cP; and/or a shear failure temperature at least about 20% higher than an equivalent composition not comprising the at least one high propylene content polymer; and/or a greater percentage fiber tear at-7 ℃ and/or-15 ℃ on corrugated board than an equivalent composition not comprising the at least one high propylene content polymer.

12. An adhesive comprising a propylene-ethylene copolymer and a high propylene content polymer, wherein the propylene-ethylene copolymer has a polydispersity of at least 3.

13. The adhesive of claim 12 wherein the high propylene content polymer is selected from the group consisting of propylene homopolymers; metallocene-catalyzed polypropylene; propylene-ethylene copolymers; metallocene-catalyzed propylene-ethylene copolymers; propene and straight-chain or branched C₄To C₂₀Copolymers of olefins; propene and straight-chain or branched C₄To C₂₀Metallocene-catalyzed copolymers of olefins; propylene, ethylene and C₄To C₂₀Terpolymers of olefins; a propylene wax; a terpolymer formed from ethylene, propylene, and a diene (EPDM), or a combination thereof.

14. The adhesive of claim 12 wherein the propylene-ethylene copolymer comprises 10 to 40 weight percent ethylene and has a softening point of 99 to 145 ℃.

15. The adhesive of claim 12 wherein the propylene-ethylene copolymer has a brookfield viscosity at 190 ℃ of less than 30,000 cps, as measured by ASTM D3236, and/or wherein the propylene-ethylene copolymer has a penetration of from 8 to 75 dmm, as measured by ASTM D5.

16. The adhesive of claim 12, wherein the propylene-ethylene copolymer has a crystallinity of less than 30% as determined using DSC according to ASTM E794-85 and a number average molecular weight (Mn) of less than 20,000 as determined by gel permeation chromatography.

17. The adhesive of claim 12, wherein the propylene-ethylene copolymer exhibits a melting temperature of 90 ℃ to 135 ℃.

18. The adhesive of claim 12, wherein the adhesive comprises:

(a) 5 to 95 weight percent of the propylene-ethylene copolymer;

(b) 10 to 90 weight percent of the high propylene content polymer;

(c) up to 70 wt% of at least one tackifier;

(d) up to 20 wt% of at least one processing oil; and

(e) not more than 20% by weight of at least one wax.

19. The adhesive of claim 11, wherein the adhesive comprises:

(a) 30 to 75 weight percent of the propylene-ethylene copolymer;

(b) 5 to 30 weight percent of the high propylene content polymer;

(c) up to 40 wt% of at least one tackifier;

(d) up to 20 wt% of at least one processing oil; and

(e) not more than 20% by weight of at least one wax.

20. An article comprising the adhesive of claim 1, wherein the article is selected from the group consisting of adhesives, sealants, caulks, roofing membranes, waterproofing membranes and liners, carpets, laminates, tapes (e.g., tamper tape, water activated tape, gummed tape, sealing tape, scrim reinforced tape, facing tape, reinforced and non-reinforced adhesive tape, box making tape, paper tape, packaging tape, HVAC reinforcement tape, masking tape, stealth tape, electrical tape, appliance tape, hockey tape, medical tape, and the like), labels (e.g., utility labels, beverage labels, freezer labels, smart labels, consumer electronics labels, and the like), caulks, polymer blends, cable coatings, molded articles, heat seal coatings, disposable hygiene products, Insulating Glass (IG) components, bridge decks, waterproofing membranes, roofing membranes, waterproofing membranes, and liners, Water-proofing compounds, underlayment, cable coating/filling compounds, sheet molding compounds, bulk molding compounds, overmolding compounds, rubber compounds, polyester composites, glass fiber reinforced plastics, wood plastic composites, polyacrylic blend compounds, lost wax precision castings, investment casting wax compositions, candles, windows, films, gaskets, seals, O-rings, automotive molded parts, automotive extruded parts, apparel articles, rubber additives/processing aids, and fibers.

Summary of The Invention

One or more embodiments of the present invention relate to copolymers comprising propylene and ethylene having a softening point in the range of 90 to 140 ℃. Furthermore, the copolymer has a penetration equal to y, defined by the formula:

y ≤ -0.000000262249x⁶+ 0.000172031278x⁵- 0.046669720165x⁴+6.701746779438x³- 537.286013331959x²+ 22,802.983472587x-400,204.018086126. In the above formula, x is the softening point of the copolymer.

Further, one or more embodiments of the present invention relate to a copolymer comprising propylene and ethylene. The copolymer has a softening point of 110 to 135 ℃ and a penetration of less than 25 dmm.

Further, one or more embodiments of the present invention relate to a copolymer comprising propylene and ethylene. The copolymer has a softening point of 90 to 121 ℃ and a penetration of less than 35 dmm.

In addition, one or more embodiments of the present invention relate to copolymers comprising propylene and ethylene. The copolymer has a softening point of 90 to less than 115 ℃ and a penetration of equal to or less than 53 dmm.

In addition, one or more embodiments of the present invention relate to low molecular weight copolymers comprising propylene and ethylene. The low molecular weight copolymer has a softening point of 90 to 140 ℃. The low molecular weight copolymer has a penetration equal to y, wherein y is defined by the formula:

y ≤ -0.000000262249x⁶+ 0.000172031278x⁵- 0.046669720165x⁴+6.701746779438x³- 537.286013331959x²+ 22,802.983472587x - 400,204.018086126，

wherein x in the above formula is the softening point of the copolymer;

wherein the low molecular weight copolymer has a molecular weight polydispersity index of about 3 to about 25, about 18% obtained by X-ray diffractionTo a crystallinity of about 30%, and at 190 as measured by ASTM D3236^◦A Brookfield viscosity at C of from about 1,000 to about 4,000 cp.

Furthermore, one or more embodiments of the present invention relate to hot melt adhesives. The hot melt adhesive contains a copolymer comprising propylene and ethylene. The copolymer has a softening point of 90 to 140 ℃ and a penetration equal to y, defined by the formula:

y ≤ -0.000000262249x⁶+ 0.000172031278x⁵- 0.046669720165x⁴+6.701746779438x³- 537.286013331959x²+ 22,802.983472587x-400,204.018086126. In the above formula, x is the softening point of the copolymer.

Further, one or more embodiments of the present invention relate to a method of manufacturing the copolymer. The process comprises reacting propylene with ethylene in the presence of a catalyst system comprising an electron donor to form the copolymer. The copolymer has a softening point of 90 to 140 ℃ and a penetration equal to y, defined by the formula:

y ≤ -0.000000262249x⁶+ 0.000172031278x⁵- 0.046669720165x⁴+6.701746779438x³- 537.286013331959x²+ 22,802.983472587x-400,204.018086126. In the above formula, x is the softening point of the copolymer.

In yet another embodiment of the present invention, a method of making a copolymer is provided. The process comprises reacting propylene with ethylene in the presence of a catalyst system comprising an electron donor to form the copolymer. The copolymer has a softening point of 110 to 140 ℃ and a penetration equal to y, defined by the formula:

y ≤ -0.000751414552642x⁴+ 0.374053308337937x³- 69.5967657676062x²+ 5,734.02599677759x-176,398.494888882. In the above formula, x is the softening point of the copolymer.

One or more embodiments of the present invention are directed to adhesive compositions comprising at least one propylene-ethylene copolymer and at least one propylene polymer, wherein the propylene-ethylene copolymer comprises at least 10 wt.% ethylene and has a softening point of at least 99 ℃.

One or more embodiments of the present invention are directed to adhesive compositions comprising at least one propylene-ethylene copolymer and at least one propylene polymer, wherein the propylene-ethylene copolymer has a polydispersity of at least 3.

Brief description of the drawings

Embodiments of the present invention are described herein with reference to the following drawings, wherein:

FIG. 1A depicts the viscoelastic characteristics of a particular propylene-ethylene copolymer made in example 1;

FIG. 1B depicts the viscoelastic characteristics of the specific propylene-ethylene copolymer made in example 1;

FIG. 2 depicts the viscoelastic characteristics of the adhesive made in example 4;

FIG. 3 depicts the viscoelastic characteristics of the adhesive made in example 5;

FIG. 4 depicts the viscoelastic characteristics of the adhesive made in example 6;

FIG. 5 depicts a comparative Aerfin ^®180 viscoelastic properties of the copolymer as a function of temperature;

FIG. 6 depicts the viscoelastic properties of low molecular weight copolymers of the present invention as a function of temperature;

FIG. 7 depicts a low molecular weight copolymer of the present invention and a comparative Aerafin ^®180 capillary rheology of the copolymer;

FIG. 8 depicts the experimental layout of molecular weights;

FIG. 9 depicts the peel strength performance of adhesive compositions of various molecular weight distributions;

FIG. 10 depicts peel strength as a function of low molecular weight copolymer content of the present invention in various adhesive formulations; and

FIGS. 11-20 depict the peel strength vs spray temperature of adhesive compositions containing the low molecular weight copolymers of the present invention, and comparative data.

Detailed Description

The present invention relates generally to amorphous propylene-ethylene copolymers and their various applications. Many of the existing propylene-ethylene copolymers currently on the market often exhibit deficiencies with respect to their softening point or hardness. The copolymers of the invention described herein exhibit improved properties not currently available in these commercially available copolymers. In particular, as described in more detail below, the copolymers of the present invention can exhibit desirable softening points and strikethrough, thereby obtaining copolymers that can be used in a variety of applications. In addition, the low molecular weight copolymers of the present invention provide additional features including a wide operating window for adhesive applications and high peel strength.

Propylene-ethylene copolymer

Commercial propylene-ethylene copolymers are often not strong enough to be used in adhesives for packaging applications or hygiene products (e.g., diapers and feminine care products). Generally, this is related to the lack of a balance between strength and adhesion properties of the copolymer. Historically, in order to produce a copolymer with sufficient strength, the ethylene content of the copolymer must be limited. It has been observed that there is a correlation between the ethylene content of a copolymer and its softening point and penetration (which is indicative of copolymer strength). In general, the ethylene content can have a negative correlation with the softening point of the copolymer and a positive correlation with the penetration of the copolymer. In other words, the more ethylene present in the copolymer, the lower the softening point of the copolymer and the higher the penetration. Thus, increasing the ethylene content of a propylene-ethylene copolymer can lower the softening point of the copolymer, but can also compromise its strength as indicated by the increased penetration.

Unlike conventional propylene-ethylene copolymers currently available, the copolymers of the present invention can exhibit desirable softening points and strikethrough at relatively high ethylene contents. As previously mentioned, it may be desirable to utilize ethylene as a comonomer in propylene copolymers due to its high availability and low cost compared to other alpha-olefins. In addition, there may be polymerization advantages to using ethylene as a comonomer, since ethylene is much more reactive than many other alpha-olefins.

According to various embodiments, the propylene-ethylene copolymers described herein may comprise different amounts of ethylene. For example, the propylene-ethylene copolymer may comprise at least 1, 3, 5,7, 10, 12, 14, 15, 17, 18, or 20 and/or no more than 70, 65, 60, 55, 50, 45, 40, 35, 30, 27, or 25 wt% ethylene. In addition, the propylene-ethylene copolymer may comprise 1 to 70, 3 to 65, 5 to 60, 7 to 55, 10 to 50, 12 to 45, 14 to 40, 15 to 35, 17 to 30, 18 to 27, or 20 to 25 weight percent ethylene.

Further, in various embodiments, the propylene-ethylene copolymers may contain varying amounts of propylene. For example, the propylene-ethylene copolymer may comprise at least 40, 50, 60, 65, or 70 and/or not more than 99, 95, 90, 85, or 80 weight percent propylene. In addition, the propylene-ethylene copolymer may comprise 40 to 99, 50 to 95, 60 to 90, 65 to 85, or 70 to 80 weight percent propylene.

In various embodiments, the copolymer may comprise at least 50, 65, 75, or 85 and/or no more than 99, 97.5, 95, or 90 weight percent of a combination of ethylene and propylene. Further, the copolymer can comprise 50 to 99, 65 to 97.5, 75 to 95, or 85 to 90 weight percent of a combination of ethylene and propylene. Additionally or alternatively, the copolymer may have a weight ratio of propylene to ethylene of at least 0.5:1, 1:1, 2:1, or 2.5:1 and/or not more than 20:1, 15:1, 10:1, or 5: 1. Further, the copolymer can have a weight ratio of propylene to ethylene of 0.5:1 to 20:1, 1:1 to 15:1, 2:1 to 10:1, or 2.5:1 to 5: 1.

In various embodiments, the copolymer may contain one or more C₄-C₁₀An alpha-olefin. As described above, C₄-C₁₀Alpha-olefins can be used to improve the resulting bond strength of the copolymer when used in an adhesive. These C₄-C₁₀The alpha-olefins may include, for example, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and combinations thereof. According to one or more embodiments, the copolymer may comprise at least 0.5, 1,2, 3, 4, or 5 and/or not more than 40, 30, 25, 20, 15, or 10 weight percent of at least one C₄-C₁₀An alpha-olefin. In addition, the copolymer may comprise 0.5 to 40, 1 to 30, 2 to 25, 3 to 20, 4 to 15, or 5 to 10 weight percent of at least one C₄-C₁₀An alpha-olefin.

As noted above, a lower softening point of the copolymer is desirable so that the copolymer can be used and processed at lower application temperatures. In various embodiments, the copolymer can have a softening point of at least 85, 90, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 113, 115, 116, 119, 120, 121, 124, 125, or 127 ℃. Additionally or alternatively, the copolymer may have a Softening Point of no greater than 145, 140, 138, 137, 136, 135, 134, 132, 130, 129, 128, 127, 126, 125, 124, 123, 122, 121, 120, 118, 117, 115, 110, or 109.9 ℃ as measured by a ring and ball apparatus using a heating rate of 5 ℃/minute and a USP Glycerin bath according to ASTM E28 Standard Test Method for software Point of resin derived from Pin Chemicals and Hydrocarbons.

Further, the copolymer can have a softening point of 85 to 145 ℃,90 to 140 ℃,90 to 110 ℃,90 to 121 ℃,90 to 115 ℃, 95 to 138 ℃, 95 to 110 ℃, 96 to 136 ℃, 97 to 135 ℃,98 to 134 ℃, 99 to 132 ℃, 100 to 130 ℃, 101 to 129 ℃, 102 to 128 ℃, 103 to 127 ℃, 104 to 126 ℃, 105 to 125 ℃, 106 to 124 ℃, 107 to 123 ℃, 108 to 122 ℃, 109 to 121 ℃, or 110 to 120 ℃ as measured according to ASTM E28 as previously described.

Despite exhibiting the low softening point described above, the copolymer may also exhibit desirable penetration values. Generally, the lower the penetration value, the higher the strength characteristics and modulus of the copolymer; however, if the penetration is too low, the adhesive properties may be adversely affected. In various embodiments, the penetrometer value of the copolymers described herein can be defined by the following formula when the softening point is from 90 to 140 ℃:

y ≤ -0.000000262249x⁶+ 0.000172031278x⁵- 0.046669720165x⁴+6.701746779438x³- 537.286013331959x²+ 22,802.983472587x-400,204.018086126. In the above formula, "y" defines the penetration (dmm) of the copolymer, and "x" is the softening point (. degree. C.) of the copolymer.

The Penetration was measured according to ASTM D5 Standard Test Method for the networking of Bituminous materials and using the following specifications:

spindle weight 47.5 +/-0.05 grams.

The weight of the snare needle assembly was 2.50 +/-0.05 grams.

The total weight of the needle and spindle assembly is 50.0 +/-0.05 grams.

Weights of 50 +/-0.05 grams should also be provided to achieve a total load of 100 grams.

The samples were conditioned in a water bath at a temperature of 25 +/-0.1 ℃ [77 +/-0.2 ° F ].

The time for the needle to penetrate the sample was 5 +/-0.1 seconds.

In various other embodiments, the penetrometer value of the copolymers described herein can be defined by the following formula when the softening point is from 110 to 140 ℃:

y ≤ -0.000751414552642x⁴+ 0.374053308337937x³- 69.5967657676062x²+ 5,734.02599677759x-176,398.494888882. In the above formula, "y" defines the penetration (dmm) of the copolymer, and "x" is the softening point (. degree. C.) of the copolymer.

In various embodiments, the copolymer can have a penetration of at least 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 20, 30, or 35 decimillimeters ("dmm"), as measured according to ASTM D5, as previously described. Additionally or alternatively, the copolymer may have a penetration of no more than 75, 73.8, 70, 60, 50, 45, 40, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, or 15 dmm, as measured according to ASTM D5, as previously described. Further, the copolymer can have a penetration of 1 to 75, 2 to 50, 3 to 30, 4 to 29, 5 to 28, 6 to 27, 7 to 26, 8 to 25, 9 to 24, 10 to 23, 11 to 22, 12 to 21, or 13 to 20 dmm, as measured according to ASTM D5, as previously described.

The copolymers may have different softening points and penetration ranges depending on their intended end use. In various embodiments, the copolymer can have a softening point of 90 to 121 ℃ and a penetration of less than 35 dmm. In other embodiments, the copolymer may have a softening point of 90 to 115 ℃ and a penetration of less than 53 dmm. In various embodiments, the copolymer can have a softening point of 110 to 138 ℃ and a penetration of 1 to 15 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 135 ℃ and a penetration of 5 to 15 dmm. Further, in certain embodiments, the copolymer may have a softening point of 110 to 130 ℃ and a penetration of 10 to 15 dmm.

In various embodiments, the copolymer can have a softening point of 110 to 137 ℃ and a penetration of 1 to 22 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 135 ℃ and a penetration of 5 to 22 dmm. In other embodiments, the copolymer may have a softening point of 110 to 135 ℃ and a penetration of 10 to 24 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 130 ℃ and a penetration of 10 to 20 dmm.

In various embodiments, the copolymer can have a softening point of 110 to 134 ℃ and a penetration of 1 to 25 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 132 ℃ and a penetration of 5 to 25 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 130 ℃ and a penetration of 10 to 25 dmm.

In various embodiments, the copolymer can have a softening point of 110 to 124 ℃ and a penetration of 1 to 30 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 122 ℃ and a penetration of 5 to 30 dmm. Further, in certain embodiments, the copolymer may have a softening point of 110 to 120 ℃ and a penetration of 10 to 30 dmm.

In various embodiments, the copolymer can have a softening point of 110 to 120 ℃ and a penetration of 30 to 50 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 120 ℃ and a penetration of 35 to 50 dmm. Further, in certain embodiments, the copolymer can have a softening point of 110 to 120 ℃ and a penetration of 30 to 45 dmm.

In various embodiments, the copolymer can have a softening point of 90 to 125 ℃ and a penetration of less than 30 dmm. Further, in certain embodiments, the copolymer may have a softening point of 90 to 123 ℃ and a penetration of less than 35 dmm. Further, in certain embodiments, the copolymer may have a softening point of 90 to 125 ℃ and a penetration of 10 to 30 dmm.

In various embodiments, the copolymer can have a softening point of 90 to 109.9 ℃ and a penetration of less than 73.8 dmm. Further, in certain embodiments, the copolymer can have a softening point of 127 to 140 ℃ and a penetration of less than 25 dmm. Further, in certain embodiments, the copolymer can have a softening point of 124 to 126 ℃ and a penetration of less than 30 dmm.

In various embodiments, the copolymer can have a softening point of 121 to 123 ℃ and a penetration of less than 40 dmm. Further, in certain embodiments, the copolymer may have a softening point of 119 to 120 ℃ and a penetration of less than 50 dmm. Further, in certain embodiments, the copolymer can have a softening point of 116 to 118 ℃ and a penetration of less than 60 dmm. In other embodiments, the copolymer may have a softening point of 113 to 117 ℃ and a penetration of less than 70 dmm.

In general, lower softening points in the copolymer can sometimes be accompanied by lower glass transition ("Tg") temperatures. In various embodiments, the copolymer can have a glass transition temperature of at least-100, -80, -60, or-40 and/or not more than about 20,0, -10, or-20 ℃ as measured by DMA. Further, the copolymer may have a Tg of-100 to 20 ℃, -80 to 0 ℃, -60 to-10 ℃ or-40 to-20 ℃ as measured by DMA.

Further, in various embodiments, the copolymer can have a melt viscosity at 190 ℃ of at least 100, 500, 1,000, 3,000, or 5,000 and/or no more than about 100,000, 75,000, 50,000, 35,000, or 25,000 cP measured according to ASTM D3236. Further, the copolymer can have a melt viscosity at 190 ℃ of 100 to 100,000, 500 to 75,000, 1,000 to 50,000, 3,000 to 35,000, or 5,000 to 25,000 cP measured according to ASTM D3236.

According to one or more embodiments, the copolymer may have a brookfield viscosity at 190 ℃ of at least 100, 300, 500, or 750 and/or no more than 30,000, 10,000, 5,000, or 2,500 cps, measured according to ASTM D3236. Further, the copolymer can have a brookfield viscosity at 190 ℃ of 100 to 30,000, 300 to 10,000, 500 to 5,000, or 750 to 2,500 cps.

In one or more embodiments, the copolymers described herein may also have a number average molecular weight (Mn) of less than 100,000, 50,000, or 25,000 as determined by gel permeation chromatography.

In various embodiments, the copolymers described herein do not exhibit a significant color change when subjected to storage conditions at elevated temperatures for extended periods of time. The copolymer of the present invention may have an initial gardner color of less than 4, 3, 2, or 1 as measured according to ASTM D1544 before any aging due to storage occurs. After heat aging at 177 ℃ for at least 96 hours, the copolymers of the present invention can exhibit a final gardner color of less than 7, 5, 3, or 2 as measured according to ASTM D1544. Thus, the copolymers of the present invention can maintain a desirable color even after long-term storage and exposure.

Further, the copolymers described herein may be amorphous or semi-crystalline. As used herein, "amorphous" means that the copolymer has a crystallinity of less than 5% as measured using differential scanning calorimetry ("DSC") according to ASTM E794-85. As used herein, "semi-crystalline" means that the copolymer has a crystallinity of 5 to 40% as measured by DSC according to ASTM E794-85. In various embodiments, the copolymer can have a crystallinity of no more than 60, 40, 30, 20, 10, 5, 4, 3, 2, or 1% as measured using DSC according to ASTM E794-85.

Low molecular weight propylene-ethylene copolymers

In various embodiments of the present invention, the propylene-ethylene copolymers of the present invention may comprise low molecular weight propylene-ethylene copolymers. These low molecular weight propylene-ethylene copolymers may have any of the features and properties described hereinabove with respect to the propylene-ethylene copolymers and are described in more detail hereinbelow.

In various embodiments of the present invention, copolymers are provided comprising propylene and ethylene and having a softening point of from 90 to 140 ℃. Further, the copolymer can have a penetration equal to y, where y is defined by the formula:

y ≤ -0.000000262249x⁶+ 0.000172031278x⁵- 0.046669720165x⁴+6.701746779438x³- 537.286013331959x²+ 22,802.983472587x-400,204.018086126, wherein "x" in the above formula is the softening point of the copolymer. Further, the copolymer can have a molecular weight polydispersity of about 3 to about 25, a crystallinity of about 18 to about 30% as measured by X-ray diffraction, and a brookfield viscosity of about 1,000 to about 4,000 cP at 190 ℃ as measured by ASTM D3236.

The low molecular weight copolymers of the present invention are useful in the manufacture of polyolefin-based hot melt adhesives for use in the manufacture of laminated articles. Adhesives comprising the low molecular weight copolymers are also useful in the preparation of personal care hygiene articles such as infant and adult incontinence diapers, pads, and feminine hygiene napkins. Despite the use of low molecular weight polyolefins, the hot melt adhesives of the present invention provide both a wide process window during the manufacture of laminated structures and high peel strength. The hot melt adhesives of the present invention can produce substantially consistent peel strengths for laminates that span a wide process window.

Furthermore, surprisingly, hot melt adhesive compositions containing the low molecular weight copolymers of the present invention can be easily applied at lower temperatures, although the low molecular weight copolymers of the present invention have relatively high softening points and crystallinities, as opposed to the softening points and crystallinities of the comparative polymers. Adhesive formulations containing the low molecular weight copolymers of the present invention can be applied using a variety of spray nozzles and slot dies at temperatures of about 120 to about 160 ℃. Other ranges are from about 130 ℃ to about 160 ℃ and from about 130 ℃ to about 150 ℃, and at various machine speeds of 100 to 600 meters per minute.

Certain properties of the low molecular weight copolymer were measured according to the procedures outlined in examples 14-16. Otherwise, the test methods listed in this specification were used.

In various embodiments, the low molecular weight propylene-ethylene copolymer may have a weight average molecular weight (Mw) of about 25,000 to about 50,000. Other exemplary ranges of Mw are from about 30,000 to about 45,000 and from about 35,000 to about 40,000. In other embodiments, the low molecular weight propylene-ethylene copolymer may have a number average molecular weight (Mn) of from about 1,000 to about 20,000. Other exemplary ranges are from about 1,500 to about 16,000, from about 2,000 to about 15,000, and from 2,500 to 14,000. In other embodiments, the z-average molecular weight (Mz) of the low molecular weight propylene-ethylene copolymer may be from about 80,000 to about 140,000. Other exemplary ranges of Mz are from about 85,000 to about 130,000, from about 90,000 to about 120,000, and from about 100,000 to about 120,000. The molecular weights (Mn, Mw and Mz) of the low molecular weight copolymers can be measured according to the procedures outlined in examples 14-16.

In various embodiments, the polydispersity (Mw/Mn) of the low molecular weight propylene-ethylene copolymer may be from about 3 to about 25, from about 4 to about 24, from about 5 to about 20, from about 6 to about 15, and from about 8 to about 10. In various embodiments, the low molecular weight propylene-ethylene copolymer may have a polydispersity of at least 3, 4, 5, 6, 7, or 8 and/or not more than 25, 24, 20, 15, or 10.

In various embodiments, the low molecular weight propylene-ethylene copolymer may have a glass transition temperature (Tg) of about-45 to about-30 ℃.

In various embodiments, the low molecular weight propylene-ethylene copolymer can have a melting temperature (Tm) of about 90 to about 138 ℃, about 100 to about 135 ℃, and about 120 to about 130 ℃.

In various embodiments, the melting energy Hm (J/g) of the low molecular weight propylene-ethylene copolymer may be less than 15J/g.

In various embodiments, the crystallinity of the low molecular weight propylene-ethylene copolymer may be from about 18 to about 30 percent as measured by X-ray diffraction. Other exemplary ranges of crystallinity include about 20 to about 30%, about 22 to about 28%, and about 22 to about 26%.

In various embodiments, the low molecular weight propylene-ethylene copolymer can have a crystallization temperature (Tc) of from about 50 to about 110 ℃, from about 60 to about 80 ℃, and from about 50 to about 70 ℃.

In various embodiments, the crystallization energy (Δ Hc) of the low molecular weight propylene-ethylene copolymer may be less than 20J/g, less than 15J/g, or less than 10J/g.

In various embodiments, the low molecular weight propylene-ethylene copolymer can have a brookfield viscosity at 190 ℃ of about 1,000 cP to about 4,000 cP, about 1,200 cP to about 3,600 cP, and about 1,500 cP to about 3,000 cP.

In various embodiments, the low molecular weight propylene-ethylene copolymer can have a storage modulus (G') at 25 ℃ of from about 1 MPa to 10MPa, from about 2 MPa to about 8 MPa, and from about 3 MPa to about 5 MPa.

In various embodiments, the low molecular weight propylene-ethylene copolymer may have a tensile strength of from about 2.5 MPa to about 4.5 MPa or from about 2.7 MPa to about 3.5 MPa.

In various embodiments, the G'/G "crossover temperature of the low molecular weight propylene-ethylene copolymer can be from about 100 to about 120 ℃ or from about 105 to about 110 ℃.

In various embodiments, the low molecular weight propylene-ethylene copolymer can have a tan delta at the crossover temperature of from about 0.35 to about 0.50 or from about 0.38 to about 0.48.

In various embodiments of the invention, the low molecular weight propylene-ethylene copolymer has a weight average molecular weight of about 25,000 to about 45,000, a number average molecular weight of about 1,000 to about 12,000, a z average molecular weight of about 90,000 to about 140,000, a polydispersity (Mw/Mn) of about 3 to about 25, a crystallinity of about 20% to about 30%, and a brookfield viscosity of 1,000 to 4,000 cP at 190 ℃. Additional exemplary characteristics of the low molecular weight propylene-ethylene copolymers used in the formulations of the present invention include a storage modulus (G' at 25 ℃) of 1 to 10 MPa; a crossover temperature (for G' and G ") of 110 to 120 ℃ and a correlation tan δ of 0.35 to 0.50; and a glass transition temperature of-40 to-25 ℃.

Process for producing propylene-ethylene copolymer

In various embodiments, the copolymer may be made by reacting propylene monomers with ethylene monomers in the presence of a catalyst system comprising at least one electron donor.

In various embodiments, the catalyst system may comprise a Ziegler-Natta catalyst. According to one or more embodiments, the Ziegler-Natta catalyst may contain a titanium-containing component, an aluminum component, and an electron donor. In certain embodiments, the catalyst comprises titanium chloride on a magnesium chloride support.

In certain embodiments, the catalyst system may comprise a heterogeneous supported catalyst system formed from a titanium compound in combination with an organoaluminum cocatalyst. In various embodiments, the cocatalyst can comprise an aluminum alkyl cocatalyst ("TEAL").

In one or more embodiments, the catalyst system can have a molar ratio of aluminum to titanium of at least 1:1, 5:1, 10:1, or 15:1 and/or not more than 100:1, 50:1, 35:1, or 25: 1. Further, the catalyst system can have a molar ratio of aluminum to titanium of 1:1 to 100:1, 5:1 to 50:1, 10:1 to 35:1, or 15:1 to 25: 1. Additionally or alternatively, in various embodiments, the catalyst system can have a molar ratio of aluminum to silicon of at least 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, or 6:1 and/or not more than 100:1, 50:1, 35:1, 20:1, 15:1, 10:1, or 8: 1. Further, the catalyst system can have a molar ratio of aluminum to silicon of 0.5:1 to 100:1, 1:1 to 50:1, 2:1 to 35:1, 2:1 to 20:1, 2:1 to 15:1, 2:1 to 10:1, or 2:1 to 8: 1.

The electron donor can improve the stereospecificity of the copolymer. However, it can be important to strictly adjust the electron donor content, since in some cases they can inhibit the catalyst activity to an unacceptable level. The electron donor used in the polymerization process may include, for example, organic esters, ethers, alcohols, amines, ketones, phenols, phosphines, and/or organosilanes. Furthermore, the catalyst system may comprise an internal donor and/or an external donor.

In various embodiments, the catalyst system comprises at least one external electron donor. In one or more embodiments, the external electron donor comprises at least one alkoxysilane. In particular, in certain embodiments, the alkoxysilane may comprise dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, or a combination thereof. Further, in some embodiments, the alkoxysilane may comprise, consist essentially of, or consist entirely of dicyclopentyldimethoxysilane.

It has been observed that the addition of the above external donor to the catalyst system can increase the hardness (i.e. reduce the penetration) and the viscosity of the copolymer. However, contrary to what has been previously observed in the prior art, the above electron donor can actually lower the softening point of the copolymer obtained, instead of increasing it. Furthermore, it has been observed that when the above-mentioned electron donors are used, substantially all (i.e., greater than 95%) of the ethylene added to the reactor during the polymerization can react. This makes it possible to obtain copolymers having a higher ethylene content and a lower propylene content. Thus, when the above electron donor is used, a propylene-ethylene copolymer having a higher ethylene content but still exhibiting a desired balance between softening point and hardness can be produced.

Further, according to various embodiments, the catalyst system may have a molar ratio of electron donor to titanium of at least 0.1:1, 0.5:1, 1:1, 1.25:1, 1.5:1, or 2:1 and/or not more than 20:1, 15:1, 10:1, 5:1, 4.5:1, or 4: 1. Further, the catalyst system can have a molar ratio of electron donor to titanium of 0.1:1 to 20:1, 0.5:1 to 15:1, 1:1 to 10:1, 1.25:1 to 5:1, 1.5:1 to 4.5:1, or 2:1 to 4: 1. Additionally or alternatively, in various embodiments, the catalyst system may have a molar ratio of TEAL co-catalyst to electron donor of at least 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, or 6:1 and/or not more than 100:1, 50:1, 35:1, 20:1, 15:1, 10:1, or 8: 1. Further, the catalyst system may comprise a molar ratio of TEAL co-catalyst to electron donor of from 0.5:1 to 100:1, from 1:1 to 50:1, from 2:1 to 35:1, from 2:1 to 20:1, from 2:1 to 15:1, from 2:1 to 10:1, or from 2:1 to 8: 1. In certain embodiments, the type of electron donor may affect the desired TEAL/electron donor ratio. For example, in embodiments where the electron donor is dicyclopentyldimethoxysilane, the TEAL/electron donor ratio may be less than 20: 1.

The catalyst system may exhibit a catalyst activity of 200 to 2,000, 400 to 1,200, or 500 to 1,000 g/g. The catalyst activity was calculated by measuring the ratio of the weight of the polymer produced in the reactor to the weight of the catalyst charged into the reactor. These measurements are based on a reaction time of 1 hour.

Since the addition of an external donor can increase viscosity and molecular weight, the addition of hydrogen may be required to act as a chain terminator during polymerization. For example, the process can be carried out at a hydrogen pressure of 5 to 100, 10 to 80, or 15 to 50 psig.

In various embodiments, the polymerization reaction may occur at a temperature of 100 to 200, 110 to 180, or 120 to 150 ℃. Further, the polymerization reaction can be conducted at a pressure of 500 to 2,000, 700 to 1500, or 800 to 1250 psig.

In certain embodiments, the reactor may comprise a stirred reactor, and the polymerization reaction may have a residence time in the reactor of 0.1 to 6, 0.5 to 4, or 1 to 2 hours. In various embodiments, ethylene may be added to the reactor as a gas and propylene may be added as a liquid.

End products incorporating the propylene-ethylene copolymers

The propylene-ethylene copolymers of the present invention and compositions comprising these copolymers described herein are useful in a variety of applications including, for example, adhesives, sealants, caulks, roofing membranes, waterproofing membranes and underlayments (underlayments), carpets, laminates, tapes (e.g., tamper evident tapes), water activated tapes, gummed tapes, sealing tapes, scrim reinforced tapes, facing tapes, reinforced and non-reinforced adhesive tapes, box making tapes (box makertapes), paper tapes, packaging tapes, HVAC strength tapes, masking tapes, concealed tapes, electrical tapes, appliance (gaffer) tapes, hockey tapes, medical tapes, and the like), labels (e.g., general purpose labels, beverage labels, freezer labels, smart labels, consumer electronics labels, and the like), caulks (massics), polymer blends, Cable coatings, molded articles, heat seal coatings, disposable hygiene products, Insulating Glass (IG) components, bridge decks, waterproofing membranes, waterproofing compounds, underlayment, cable coating/filling compounds, sheet molding compounds, bulk molding compounds, overmolding compounds, rubber compounds, polyester composites, glass fiber reinforced plastics, wood plastic composites, polyacrylic blend compounds, lost wax precision castings, investment casting wax compositions, candles, windows, films, gaskets, seals, O-rings, automotive molded parts, automotive extruded parts, apparel articles, rubber additives/processing aids, and fibers.

Films comprising the inventive propylene-ethylene copolymers and compositions containing these copolymers described herein include, but are not limited to, multilayer films, coextruded films, calendered films, and cast films. Laminates comprising the propylene-ethylene polymers of the present invention or compositions comprising the propylene-ethylene polymers of the present invention include, but are not limited to, paper-foil laminates, paper-film laminates, and nonwoven-film laminates.

Adhesive compositions comprising the propylene-ethylene copolymers of the invention and compositions containing these copolymers described herein include packaging adhesives, food contact grade adhesives, indirect food contact packaging adhesives, product assembly adhesives, woodworking adhesives, flooring adhesives, automotive assembly adhesives, structural adhesives, mattress adhesives, Pressure Sensitive Adhesives (PSAs), PSA tapes, PSA labels, PSA protective films, self-adhesive films, laminating adhesives, flexible packaging adhesives, heat seal adhesives, industrial adhesives, sanitary non-woven construction adhesives, sanitary core integrity adhesives (hygienic) and sanitary elastic attachment adhesives.

In certain embodiments, the copolymers described herein are useful in adhesives such as hot melt adhesives, water-based adhesives, solvent-based adhesives, hot melt pressure sensitive adhesives, solvent-based pressure sensitive adhesives, hot melt nonwoven/hygiene adhesives, hot melt product assembly adhesives, hot melt woodworking adhesives, and hot melt packaging adhesives. In particular, due to their unique combination of softening point and penetration as previously described, adhesives made from the copolymers of the present invention can be used in a variety of end products, including sanitary packaging and other packaging applications. In many embodiments, various properties of the copolymers of the present invention, such as softening point and penetration, can be selected to suit the intended end use of the composition incorporating the copolymer.

In certain embodiments, the copolymers of the present invention are useful in the manufacture of adhesives for packaging, product assembly, film lamination, woodworking, and/or profile sheathing.

In various embodiments, the adhesive of the present invention comprises a hot melt adhesive. The hot melt adhesive may be applied to the substrate in its molten state and cooled to harden the adhesive layer. Such adhesives are widely used in various commercial and industrial applications, such as product assembly and packaging. In these applications, an adhesive is applied to at least one substrate to bond the substrate to a similar or different second substrate.

Adhesive formulators and users often desire heat stable, light colored hot melt adhesives that have an advantageous balance of physical properties including high temperature resistance, chemical resistance, bond strength, viscosity, adhesion to various substrates, and open and set times (open and set times) that can be tailored to specific use and application conditions. The balance of properties desired varies with the application, and the hot melt compositions of the present invention described herein provide an improved balance of properties for a variety of end uses.

The hot melt adhesive composition may have melt rheology and thermal stability suitable for use in conventional hot melt adhesive application equipment. In various embodiments, the blend components of the hot melt adhesive composition have a low melt viscosity at the application temperature, thereby facilitating flow of the composition through a coating apparatus, such as a coating die or nozzle.

The hot melt adhesive composition can be used to bond a variety of substrates including, for example, paperboard, coated paperboard, fiberboard, unused and recycled kraft paper, high and low density kraft paper, particle board, treated and coated kraft paper and particle board, as well as corrugated forms thereof, clay-coated particle board carton stock, composites, leather, polymeric films (e.g., polyolefin films (e.g., polyethylene and polypropylene), polyvinyl chloride films, ethylene vinyl acetate films, polyester films, metallized polymeric films, multilayer films, and combinations thereof), fibers and substrates made from fibers (e.g., unused fibers, recycled fibers, synthetic polymeric fibers, cellulosic fibers, and combinations thereof), release liners, porous substrates (e.g., woven webs, nonwoven scrims, and perforated films), cellulose-based substrates, cellulosic-based substrates, paper-based substrates, Sheets (e.g., paper, and fibrous sheets), paper products, tape backings, and combinations thereof. Useful composite materials include, for example, particle board laminated to a metal foil (e.g., aluminum foil), which optionally may be laminated to at least one polymeric film, particle board bonded to a film, kraft paper bonded to a film (e.g., polyethylene film), and combinations thereof.

The hot melt adhesive composition can be used to bond a first substrate to a second substrate in a variety of applications and configurations, including, for example, packaging, bags, boxes, cartons, cases, trays, multi-layer bags, articles including accessories (e.g., straw attached to a beverage box), ream wrap (ream wrap), cigarettes (e.g., plugwrap), filters (e.g., pleated filters and filter frames), book bindings, footwear, disposable absorbent articles (e.g., disposable diapers, sanitary napkins, medical dressings (e.g., wound care products), bandages, surgical pads, drapes, surgical gowns, and meat wraps), paper products, including, for example, paper towels (e.g., multipurpose towels), toilet tissue, facial tissue, wet wipes, paper towels (e.g., paper towels), sheets, mattress covers, and components of absorbent articles, including, for example, absorbent elements, absorbent cores, absorbent articles, Impermeable layers (e.g., backings), tissues (e.g., packaging tissues), liquid-collecting layers, and woven and nonwoven web layers (e.g., cover papers, absorbent papers), and combinations thereof.

The hot melt adhesive composition can also be used to form laminates of porous substrates and polymeric films, such as those used to make disposable articles including, for example, medical drapes, medical gowns, drapes, feminine hygiene products, diapers, adult incontinence products, absorbent pads for animals (e.g., pet pads) and humans (e.g., bodies and cadavers), and combinations thereof.

The hot melt adhesive composition can be applied to a substrate in any useful form, including, for example, as fibers, as coatings (e.g., continuous and discontinuous coatings (e.g., random, pattern, and array)), as beads, as films (e.g., continuous and discontinuous films), and combinations thereof, using any suitable application method, including, for example, slot coating, spraying (e.g., spiral spraying, random spraying, and random fiberization (e.g., melt blowing)), foaming, extrusion (e.g., applying beads, fine line extrusion, single screw extrusion, and twin screw extrusion), wheel coating, non-contact coating, gravure printing, embossing rollers, roll coating, transfer coating, screen printing, flexography, and combinations thereof.

Typical, but non-limiting, industrial applications of the hot melt adhesive composition include packaging, particularly for low temperature applications, such as freezer packaging for dairy products or for food products, and in disposable hygienic consumer products, such as diapers, feminine care pads, sanitary napkins, and the like. Conventional end-use applications (e.g., book binding, woodworking, and labeling) would also benefit from low temperature flexibility, heat resistance, and end-use efficiency in automated equipment that applies the hot melt adhesive composition to various substrates.

Furthermore, in various embodiments, the copolymers of the invention described herein can also be used to modify existing polymer blends, which are typically used in plastics, elastomeric applications, roofing applications, cable filling, and tire modification. The copolymers of the present invention can improve the adhesion, processability, stability, viscoelasticity, thermal properties and mechanical properties of these polymer blends.

In various embodiments, the propylene-ethylene copolymers of the present invention may be modified to produce graft copolymers. In such embodiments, the copolymers of the present invention may be grafted with maleic anhydride, fumaric and maleic esters, methacrylic esters (e.g., glycidyl methacrylate and hydroxyethyl methacrylate), methacrylic acid, vinyl derivatives, silane derivatives, or combinations thereof. These graft copolymers may be made using any conventional method known in the art, including, for example, transesterification and free radical induced coupling.

The various end uses and end products described above may use the copolymers of the present invention by themselves or may be combined with other additives and polymers. Suitable polymers that can be combined with the copolymers of the present invention to form polymer blends can include, for example, isoprene-based block copolymers; a butadiene-based block copolymer; a hydrogenated block copolymer; ethylene-vinyl acetate copolymers; a polyester; a polyester-based copolymer; chloroprene rubber; a carbamate; acrylic acids; a polyacrylate; acrylate copolymers such as, but not limited to, ethylene-acrylic acid copolymers, ethylene-n-butyl acrylate copolymers and ethylene-methyl acrylate copolymers; polyether ether ketone; a polyamide; styrenic block copolymers; hydrogenated styrenic block copolymers; random styrenic copolymers; ethylene-propylene rubbers; ethylene-vinyl acetate copolymers; butyl rubber; styrene-butadiene rubber; butadiene-acrylonitrile rubber; natural rubber; a polyisoprene; polyisobutylene; polyvinyl acetate; and a polyolefin.

The polyolefin used in the present invention with the propylene-ethylene copolymer of the present invention may be any polyolefin known in the art. In one embodiment of the present invention, the polyolefin may be at least one selected from the group consisting of: amorphous polyolefins, semi-crystalline polyolefins, alpha-polyolefins, reactor-ready polyolefins, metallocene-catalyzed polyolefin polymers and elastomers, reactor-made (reactor-made) thermoplastic polyolefin elastomers, olefin block copolymers, thermoplastic polyolefins, atactic polypropylene, polyethylene, ethylene-propylene polymers, propylene-hexene polymers, ethylene-butene polymers, ethylene-octene polymers, propylene-butene polymers, propylene-octene polymers, metallocene-catalyzed polypropylene polymers, metallocene-catalyzed polyethylenePolymers, propylene-based terpolymers (including ethylene-propylene-butene terpolymers), copolymers made of propylene and a linear or branched C₄-C₁₀Copolymers made from alpha-olefin monomers, made from ethylene and linear or branched C₄-C₁₀Copolymers made from alpha-olefin monomers, and functionalized polyolefins.

There are a variety of methods in the art for functionalizing polymers that can be used with the polymers described herein. These include selective oxidation, free radical grafting, ozonolysis, epoxidation, and the like. Functionalized components include, but are not limited to, functionalized olefin polymers (e.g., functionalized C₂To C₄₀Homopolymer, functionalized C₂To C₄₀Copolymers, functionalized high Mw waxes), functionalized oligomers (e.g., functionalized low Mw waxes, functionalized tackifiers), beta nucleating agents, and combinations thereof. Functionalized olefin polymers and copolymers useful in the present invention include maleated polyethylene, maleated metallocene polypropylene, maleated ethylene propylene rubber, maleated polypropylene, maleated ethylene copolymers, functionalized polyisobutylene (typically functionalized with maleic anhydride to form succinic anhydride), and the like.

In various embodiments, the propylene-ethylene copolymers of the present invention described herein can be used to make hot melt adhesives. According to one or more embodiments, the adhesive may comprise at least 1,5, 10, 15, 20, 25, 30, 35, 40, or 45 and/or no more than 95, 90, 80, 70, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or 10 weight percent of the copolymer of the present invention. Furthermore, the adhesive may comprise 1 to 95, 5 to 90, 10 to 80, 20 to 70, 30 to 60, or 40 to 55 weight percent of the copolymer of the invention. In certain embodiments, the adhesive may consist entirely of the copolymer of the present invention.

In addition, depending on the intended end use, these hot melt adhesives may also contain various additives including, for example, polymers, tackifiers, processing oils, waxes, antioxidants, plasticizers, pigments, and fillers.

In various embodiments, the adhesive may comprise at least 10, 20, 30, or 40 and/or no more than 90, 80, 70, or 55 weight percent of at least one polymer other than the copolymer of the present invention. Furthermore, the adhesive may comprise 10 to 90, 20 to 80, 30 to 70 or 40 to 55 wt% of at least one polymer different from the copolymer of the invention. These polymers may include any of the polymers listed above.

In addition, it has been found that blends of the copolymers of the present invention with various types of polyolefins can provide adhesives with improved adhesion, bond strength, high temperature resistance, viscosity, and open and cure times. Thus, in various embodiments, the above-described polymers that may be combined with the propylene-ethylene copolymers of the present invention may comprise at least one polyolefin. In certain embodiments, the adhesive may comprise, in addition to the propylene-ethylene copolymer described above, at least 1,5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 weight percent of at least one polyolefin. Additionally or alternatively, the adhesive may comprise no more than 99, 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5 wt% of at least one polyolefin in addition to the propylene-ethylene copolymer described above. For example, the adhesive may comprise 1 to 90, 1 to 60, 1 to 40, 1 to 20, 10 to 90, 20 to 80, 20 to 40, 30 to 70, 30 to 40, or 40 to 55 weight percent of at least one polyolefin. In one or more embodiments, the polyolefins may be amorphous polyolefins having a heat of fusion of less than 25J/g or less than 15J/g.

Commercial examples of acceptable amorphous polyolefins include Aerafin from Eastman Chemical ^TM17; aerfin by Eastman Chemical ^TM180, Rextac manufactured by REXtac LLC^TMPolymers, including Rextac^TME-63, e-65, 2760, 2815 and 2830; vestoplast^®Including Vestoplast^®408 and 708; and Eastoflex by Eastman chemical^®Including Eastoflex^®E1060 and P1010.

Some examples of metallocene-catalyzed polymers include polyolefins such as polyethylene, polypropylene and copolymers thereof, such as the groups sold by ExxonMobil Chemical under the trade name VIS Α Μ Α cell xElastomers in polypropylene, and polyethylene-based elastomers, such as those sold by the Dow Chemical Company under the trade names AFFINITY and ENGAGE ™ chambers. Other metallocene-catalyzed polymers include the polyolefin elastomers VISTA MAXX. sup.8816, VISTA MAXX. sup.2230 and ENGAGE. sup.8200. AFFINITY-like GA1900 has a density of 0.870 g/cm³According to ASTM D792, a heat of fusion of 46.1J/g, and a Brookfield viscosity of 8,200 cP at 177 ℃ according to ASTM D1084. AFFINITY-GA 1950 has a density of 0.874 g/cm³According to ASTM D792, a heat of fusion of 53.4J/g and a Brookfield viscosity of 17,000 cP at 177 ℃ according to ASTM D1084. ENGAGE 8200 with a density of 0.87 g/cm³According to ASTM D792 and a melt index at 190 ℃ of 5 g/10 min. These polyolefin elastomers are compatible with the copolymers of the present invention when used in hot melt adhesives.

In one embodiment of the invention, the propylene-ethylene copolymers of the present invention may be used with at least one high propylene content polymer to make compositions useful as adhesives. As used herein, a high propylene content polymer is a polymer comprising at least 60 mole% propylene monomer. In other embodiments of the invention, the high propylene content polymer comprises at least 65, 70, 75, 80, 85, 90, 95 mole percent propylene monomer. In another embodiment, the high propylene content polymer is a homopolymer of propylene. The high propylene content polymer may be any polymer known in the art including homopolymers, copolymers, terpolymers and propylene waxes. Other monomers used include straight or branched C₂-C₂₀An olefin. As used in this disclosure, a "wax" is defined as a polymer or oligomer having a heat of fusion greater than 50 joules/gram and a viscosity no greater than 750 Centipoise (CP) at 190 ℃.

Examples of high propylene content polymers include, but are not limited to, propylene homopolymers; metallocene-catalyzed polypropylene; propylene-ethylene copolymers; metallocene-catalyzed propylene-ethylene copolymers; propene and straight-chain or branched C₄To C₂₀Copolymers of olefins; propene and straight-chain or branched C₄To C₂₀Metallocene-catalyzed copolymers of olefins; propylene, ethylene and C₄To C₂₀Terpolymers of olefins; a propylene wax; a terpolymer formed from ethylene, propylene, and a diene (EPDM), or a combination thereof.

Suitable high propylene content polymers are available commercially under a variety of trademarks including, but not limited to, the L-MODU series trademarks sold, for example, by Idemitsu Kosan Co., Ltd (Japan), including, for example, L-MODU S400, S600 and S900, the VISTA AX series and ACHIEVE series trademarks sold by ExxonMobil Chemical Company (Houston, Texas), including, for example, VISTA AX 8880 and ACHIEVE 6936; and polymers LlCOCENE @ 2602 and 6502 sold by Clariant Int' l Ltd. (Muttenz, Switzerland), and EASTMAN G-3015 sold by Eastman chemical company. Examples of suitable high polypropylene content waxes are commercially available under a variety of trademarks including, but not limited to, EPOLENE N15 from Westlake Chemical Corporation (Houston, Texas), HONEYWELL A-C1089 and A-C596 from Honeywell Int' l Inc. (Morristown, New Jersey), and LlCOCENE 6102 and MA6252 from Clariant.

In various embodiments, the olefin polymer comprises a mixture of at least two different olefin polymers, such as a blend comprising an olefin homopolymer and an olefin copolymer, a blend comprising different olefin homopolymers of the same or different monomers, a blend comprising different olefin copolymers, and various combinations thereof. Useful olefin polymers also include, for example, modified, unmodified, grafted, and ungrafted olefin polymers, unimodal olefin polymers, multimodal olefin polymers, and combinations thereof.

In various embodiments of the present invention, the propylene polymer preferably comprises at least 50 mole%, at least about 60 mole%, at least about 70 mole%, at least about 80 mole%, at least about 90 mole%, at least about 95 mole%, or even from about 50 mole% to about 100 mole% propylene. The propylene polymer optionally comprises at least 2 mole%, at least about 5 mole%, at least about 10 mole%, at least about 20 mole%, at least about 30 mole%, no more than about 50 mole%, or even from about 20 mole% to about 50 mole% of at least one alpha-olefin comonomer.

In various embodiments, these added polyolefins may improve the cohesive strength, adhesive properties, tack, low temperature flexibility, overall crystallinity, and/or high temperature resistance of the adhesives of the invention. Furthermore, the addition of the aforementioned polyolefins may reduce the production cost of the adhesive due to its wide availability.

In certain embodiments, the adhesive may comprise the propylene-ethylene copolymer described above and a metallocene-catalyzed polyethylene copolymer, such as an ethylene-octene copolymer. In such embodiments, the propylene-ethylene copolymers of the present invention may be used to replace polyethylene in various types of adhesives, such as those used in packaging applications.

In certain embodiments, the added polymer and/or polyolefin may be functionalized with groups including, but not limited to, silanes, anhydrides (such as maleic anhydride), hydroxyl, ethoxy, epoxy, siloxane, amine, aminosiloxane, carboxyl, and acrylate at the polymer chain ends and/or at pendant positions in the polymer.

Additional polymers and polyolefins that may be added to the adhesives of the present invention may be prepared by Ziegler-Natta catalysts, single site catalysts (metallocenes), multiple site catalysts, non-metallocene heteroaryl catalysts, combinations thereof, or other polymerization methods. The additional polymers may comprise a combination of amorphous, semi-crystalline, random, branched, linear, or block structures.

Any conventional polymerization synthesis method can be used to prepare the additional polyolefin component. In one or more embodiments, one or more catalysts (which are typically metallocene catalysts or Zeigler-Natta catalysts) are used in the polymerization of an olefin monomer or monomer mixture. Polymerization processes include high pressure, slurry, gas phase, bulk, suspension, supercritical or solution phase, or combinations thereof. The catalyst may be in a homogeneous solution, supported form, or a combination thereof. The polymerization may be carried out by a continuous, semi-continuous, or batch process, and may include the use of chain transfer agents, scavengers, or other such additives as are deemed suitable. In one or more embodiments, the additional polymer is produced using a single polymerization catalyst in a single or multiple polymerization zones. Metallocene (or heterophasic) polymers are typically manufactured using a blend of metallocene catalysts that achieve the desired heterophasic structure.

In various embodiments, the crystalline content of the added polymer or polyolefin may increase the cohesive strength of the adhesive. Generally, adhesive formulations based on metallocene polymerized semi-crystalline copolymers can ultimately develop sufficient crystalline content over time to achieve good bond strength in the formulation.

In various embodiments, the adhesive may comprise at least 10, 20, 30, or 40 and/or no more than 90, 80, 70, 55, 50, 45, or 40 weight percent of at least one tackifier. In addition, the adhesive may comprise 10 to 90, 20 to 80, 20 to 40, 20 to 30, 30 to 70, or 40 to 55 weight percent of at least one tackifier. The tackifier imparts tack to the adhesive and may also reduce the viscosity of the adhesive. Lower viscosity can improve application flow characteristics, enable easier processing, reduce energy requirements, and reduce processing temperatures. The lower viscosity also helps the adhesive to "wet" or substantially uniformly coat surfaces and penetrate substrates. Tack is required in most adhesive formulations in order to properly join the articles before the hot melt adhesive sets. The desirability and selection of a particular tackifier may depend on the particular type of olefin copolymer and additional polymer used.

Suitable tackifiers may include, for example, cycloaliphatic hydrocarbon resins, C₅A hydrocarbon resin; c₅/C₉A hydrocarbon resin; aromatic modified C₅A resin; c₉A hydrocarbon resin; pure monomer resins, e.g. styrene with alpha-methylstyrene, vinyltoluene, p-methylstyrene, indene, methylindene, C₅Resin and C₉A copolymer of a resin; a terpene resin; terpene phenolic resin; terpene styrene resin; rosin esters; modified rosin esters; liquid resins of fully or partially hydrogenated rosin; fully or partially hydrogenated rosin esters; fully or partially hydrogenated modified rosin resins; fully or partially hydrogenated rosin alcohols; fully or partially hydrogenated C₅A resin; fully or partially hydrogenated C₅/C₉A resin; fully or partially hydrogenated aromatic modifiedC₅A resin; fully or partially hydrogenated C₉A resin; fully or partially hydrogenated pure monomer resins; fully or partially hydrogenated C₅A cycloaliphatic resin; fully or partially hydrogenated C₅cycloaliphatic/styrene/C₉A resin; fully or partially hydrogenated cycloaliphatic resins; and combinations thereof. Exemplary commercially available hydrocarbon resins include Regalite^TMHydrocarbon resin (Eastman Chemical). In certain embodiments, the tackifier may comprise a functionalized tackifier.

In various embodiments, the binder may comprise at least 1,2, 5, 8, or 10 and/or no more than 40, 30, 25, 20, or 15 weight percent of at least one processing oil. Furthermore, the binder may comprise 2 to 40, 5 to 30, 8 to 25 or 10 to 20 wt% of at least one processing oil. The process oil can include, for example, mineral oil, naphthenic oil, paraffinic oil, aromatic oil, castor oil, rapeseed oil, triglyceride oil, or combinations thereof. As will be appreciated by those skilled in the art, the processing oil may also include extender oil, which is commonly used in adhesives. The use of oil in the adhesive may be desirable if the adhesive is to be used as a pressure sensitive adhesive to make a tape or label or as an adhesive to bond nonwoven articles. In certain embodiments, the adhesive may not contain any processing oil.

In various embodiments, the adhesive may comprise at least 1,2, 5, 8, or 10 and/or no more than 40, 30, 25, 20, or 15 weight percent of at least one wax. In addition, the adhesive may comprise 1 to 40, 5 to 30, 8 to 25, or 10 to 20 weight percent of at least one wax. The wax serves to reduce the overall viscosity of the adhesive, thereby liquefying it and enabling the hot melt adhesive to be properly applied or coated onto the intended substrate. The type and melting point of the wax, as well as its compatibility with the other components of the adhesive composition, control the open time and cure speed of the adhesive. Open time is known in the art as the amount of time the adhesive wets and bonds to the substrate after application. Any conventionally known wax suitable for use in formulating hot melt adhesives may be used in the practice of the present invention.

In one embodiment of the present invention, when the propylene-ethylene copolymer of the present invention is used with a propylene polymer as the propylene wax, no other wax may be required.

Suitable waxes may include, for example, microcrystalline waxes, paraffin waxes, waxes made by the fischer-tropsch process, functionalized waxes (maleated, fumarated, or functional waxes, etc.), polyolefin waxes, petroleum waxes, polypropylene waxes, polyethylene waxes, ethylene vinyl acetate waxes, and vegetable waxes. If the adhesive is used as a hot melt packaging adhesive, it may be desirable to use a wax in the adhesive.

Non-limiting examples of commercially available waxes suitable for the present invention include Sasol, available from Sasol Wax Americas, inc^®H-1; A-C ™ 9 and A-C810, available from Honeywell International Inc.; EPOLENE ™ N-15 available from Eastman chemical; and POLYWAX-cells 400, 850, 1000, and 3000 from Baker Hughes Inc.

Other exemplary waxes include, but are not limited to, Evonik lipocene ™ PE 4201; westlake EPOLENE C-10, EPOLENE C-17 and EPOLENE C-18; and microcrystalline wax Be Square chamber 195.

As used herein, "functionalized" means that the component is prepared in the presence of a functional group incorporated into the component or contacted with a functional group and optionally a catalyst, heat, initiator, or source of free radicals such that all or a portion of the functional group (e.g., maleic acid or maleic anhydride) is incorporated, grafted, bonded, physically attached, and/or chemically linked to the polymer.

Exemplary functionalized wax polymers useful as the functionalizing component include those modified with alcohols, acids, ketones, anhydrides, and the like. Commercially available functionalized waxes include maleated polypropylene available from Chusei under the trade name Μ Α Ρ p 40; maleated metallocene wax (as available from Clariant as TP LICOCENE p 1602); maleated polyethylene waxes and maleated polypropylene waxes available from Westlake under the tradenames EPOLENE C-16, EPOLENE C-18, EPOLENE e 43; EASTMAN G-3003 from Eastman Chemical; maleated polypropylene wax licoontar 504 available from Clariant; graft functional polymers available from Dow Chemical co under the trade names AMPLIFY Α 100, AMPLIFY Α 102, AMPLIFY 103, AMPLIFY GR202, AMPLIFY GR 205, AMPLIFYGR 207, AMPLIFY GR 208, AMPLIFY GR 209 and AMPLIFY VA 200; and CERAMER maleated ethylene polymers available from Baker Hughes under the tradenames CERAMER 1608, CERAMER1251, CERAMER 67 and CERAMER 24. Useful waxes also include polyethylene and polypropylene waxes having an Mw of 15,000 or less, preferably 3,000 to 10,000, and a crystallinity of 5 wt% or more, preferably 10 wt% or more, with a functional group content of up to 10 wt%. Additional functional polymers that may be used as functional components include A-C575P, A-C573P, A-C596A, A-C beta 596P, A-C beta 597A, A-C beta 597P, A-C beta 950P, A-C beta 1221, A-C395A, A-C1302P, A-C540, A-C54A, A-C629, A-C629A, A-C307 and A-C307A, available from Honeywell International Inc.

In certain embodiments, the adhesive may not comprise a wax. For example, the adhesive may comprise less than 10, 5, 4, 3, 2, or 1 weight percent of a wax, such as, but not limited to, a polyethylene wax and/or a fischer-tropsch wax.

In various embodiments, the adhesive may comprise at least 0.1, 0.2, 0.5, 1,2, or 3 and/or no more than 20, 10, 8, 5, 1, or 0.5 weight percent of at least one antioxidant. Furthermore, the adhesive may comprise 0.1 to 20, 1 to 10, 2 to 8, or 3 to 5 weight percent of at least one antioxidant.

In various embodiments, the adhesive may comprise at least 0.5, 1,2, or 3 and/or no more than 20, 10, 8, or 5 weight percent of at least one plasticizer. Furthermore, the adhesive may comprise 0.5 to 20, 1 to 10, 2 to 8 or 3 to 5 wt% of at least one plasticizer. Suitable plasticizers may include, for example, olefin oligomers, low molecular weight polyolefins such as liquid polybutene, polyisobutylene, mineral oil, dibutyl phthalate, dioctyl phthalate, chlorinated paraffins, and phthalate-free plasticizers. Commercially available plasticizers may include, for example, Benzoflex^TMPlasticizer (Eastman Chemical); eastman 168^TM（Eastman Chemical）；Oppanol^®B10 (BASF); REGALREZ 1018 (Eastman Chemical); calsol5550 (Calumet Lubricants); kaydol oil (Chevron); or ParaLux oil (Chev)ron）。

In various embodiments, the adhesive may comprise at least 10, 20, 30, or 40 and/or no more than 90, 80, 70, or 55 weight percent of at least one filler. Furthermore, the adhesive may comprise 1 to 90, 20 to 80, 30 to 70, or 40 to 55 weight percent of at least one filler. Suitable fillers may include, for example, carbon black, calcium carbonate, clay, titanium oxide, zinc oxide, or combinations thereof.

The adhesive composition may be produced using conventional techniques and equipment. For example, the components of the adhesive composition may be blended in a mixer, such as a sigma blade mixer, a plastometer, a Brabender mixer, a twin screw extruder, or a tank blender (pint tank). In various embodiments, the adhesive can be formed into a desired form, such as a tape or sheet, by suitable techniques, including, for example, extrusion, compression molding, calendering or roll coating techniques (e.g., gravure, reverse roll, etc.), curtain coating, slot die coating, or spray coating.

In addition, the adhesive may be applied to the substrate by a solvent casting method or by melting the adhesive and then using conventional hot melt adhesive application equipment known in the art. Suitable substrates may include, for example, nonwovens, textiles, paper, glass, plastics, films (polyethylene, polypropylene, polyester, etc.), and metals. Generally, about 0.1 to 100 g/m may be used²Is applied to a substrate.

According to one or more embodiments, the hot melt adhesive may have a brookfield viscosity at 177 ℃ of at least 100, 300, 500, 750, or 1,000 and/or not more than 30,000, 10,000, 5,000, 4,000, 3,000, or 2,500 cps measured according to ASTM D3236. Further, the hot melt adhesive can have a brookfield viscosity at 177 ℃ of 100 to 30,000, 300 to 10,000, 500 to 5,000, or 750 to 2,500 cps. Additionally or alternatively, the hot melt adhesive may have a loop tack (loop tack) of 0.1, 0.5, 1, or 1.5 and/or not more than 20, 15, 10, or 5 lbf, measured according to ASTM D6195. Further, the hot melt adhesive can have an loop tack of 0.1 to 20, 0.5 to 15, 1 to 10, or 1.5 to 5 lbf, measured according to ASTM D6195.

Further, in various embodiments, the hot melt adhesive can have a peel strength of at least 1,2, 5, 10, or 15 and/or not more than 50, 40, 35, 30, or 25 g/mm, measured according to ASTM D903. Further, the hot melt adhesive can have a peel strength of 1 to 50, 2 to 40, 5 to 35, 10 to 30, or 15 to 25 g/mm measured according to ASTM D903. Additionally or alternatively, the hot melt adhesive can have a 90 ° peel strength of at least 0.05, 0.1, 0.2, or 0.5 and/or not more than 20, 10, 5, or 1 lbf/inch, measured according to ASTM D903. Further, the hot melt adhesive can have a 90 ° peel strength of 0.05 to 20, 0.1 to 10, 0.2 to 5, or 0.5 to 1 lbf/inch, measured according to ASTM D903.

According to various embodiments, adhesives containing the copolymers of the present invention may have a wide operating window and may have an application window of 80 to 230 ℃. This wide operating window can be demonstrated by the peel strength of the adhesive at different temperatures. For example, the added level may be 0.5-30 gsm. In one or more embodiments, the hot melt adhesive can have a peel strength of at least 2,5, 25, or 40 and/or not more than 250, 200, or 175g/mm, measured according to ASTM D903, for samples applied at lower temperatures (e.g., 100 to 145 ℃). Further, the hot melt adhesive can have a peel strength of 2 to 250, 25 to 200, or 40 to 175g/mm, measured according to ASTM D903, for samples applied at lower temperatures (e.g., 100 to 145 ℃). Additionally or alternatively, the hot melt adhesive may have a peel strength of at least 1,5, 30 or 40 and/or not more than 250, 200 or 150 g/mm, measured according to ASTM D903, for samples applied at higher temperatures (e.g., 145 to 180 ℃). Further, the hot melt adhesive can have a peel strength of 1 to 250, 30 to 200, or 40 to 150 g/mm, measured according to ASTM D903, for samples applied at higher temperatures (e.g., 145 to 180 ℃).

According to one or more embodiments, the hot melt adhesive may have a probe tack force of at least 0.1, 0.2, or 0.3 and/or not more than 5, 3, 2, or 1 kg, measured according to ASTM D9279. Furthermore, the hot melt adhesive may have a probe tack force of 0.1 to 3, 0.2 to 2, or 0.3 to 5 kg, measured according to ASTM D9279. Further, in various embodiments, the hot melt adhesive can have a holding power at 50 ℃ of at least 0.1, 0.5, or 1 and/or not more than 50,000, 10,000, 5,000, 1,000, 500, 100, 50, 20, 10, 7, or 4 hours, measured according to ASTM D3654. Further, the hot melt adhesive may have a holding power at 50 ℃ of 0.1 to 10, 0.5 to 7, or 1 to 4 hours measured according to ASTM D3654.

In other embodiments, the hot melt adhesive may exhibit a holding power at 60 ℃ of at least 5, 15, 20, or 25 minutes and/or not more than 150 minutes. Additionally or alternatively, the hot melt adhesive may exhibit a holding power at 50 ℃ of at least 400, 600, 800, or 1,000 minutes. The retention at 50 ℃ and 60 ℃ can be measured by the following method: the glued carton substrate is stabilized at room temperature (which is typically about +/-20 to 23 ℃) overnight, and then the substrate is hung in a peel mode in a shear bank oven (shear bank oven). The weight was then suspended below the glue base. The time to drop the weight due to failure was recorded for each specimen. A minimum of eight specimens are required for this test. The parameters of the test are listed below.

Standard of merit	Unit of	Condition
			Size of sample	mm		25×60
Application temperature	C						180+/-2
			Open time	s	2
Curing time	s	2
			Linear velocity	m/min	15
Bonding pressure	kgf	1.2 (0.08kgf/cm2)
			Coating weight	g/m	3+/-0.09
Suspended weight	g	500

According to various embodiments, the hot melt adhesive may have a peel failure temperature ("PAFT") of at least 2, 10, 25, or 45 and/or not more than 200, 120, or 80 ℃ measured according to ASTM D4498. Further, the hot melt adhesive may have a PAFT of 2, 10 to 200, 25 to 120, or 45 to 80 ℃ measured according to ASTM D4498. Additionally or alternatively, the hot melt adhesive may have a shear failure temperature ("SAFT") of at least 2,5, 10, 25, 50, 75, or 90 and/or not more than 200, 150, or 125 ℃ measured according to ASTM D4498. Further, the hot melt adhesive may have a SAFT of 2 to 200, 50 to 150, or 75 to 125 ℃ measured according to ASTM D4498.

In various embodiments, the hot melt adhesive may exhibit an effective cure time of at least 0.1, 0.5, or 1 second and/or no more than 5 seconds. In other embodiments, the hot melt adhesive may exhibit an open time of at least 1,5, or 10 and/or no more than 40, 30, or 20 seconds.

In various embodiments, the hot melt adhesive may exhibit a low temperature performance fiber tear ("LTFT") at-15 ℃ of at least 65, 70, 75, 80, or 85%. Additionally or alternatively, the hot melt adhesive may exhibit a LTFT at-25 ℃ of at least 40, 50, 60, 70 or 80%. The LTFT test involves manually tearing the glued carton substrate by hand at-15 ℃ or-25 ℃. The glued carton base must be stable at-15 c or-25 c for at least 10 hours before tearing. The hot melt adhesive is considered to pass the test if 90% of the fibers of the substrate break, and therefore is considered to perform well at-15 ℃ or-25 ℃. A minimum of 10 specimens were tested per test. The LTFT test parameters are listed below:

standard of merit	Unit of	Condition
			Size of sample	mm		50×100
Application temperature	C						180+/-2
			Open time	s	2
Curing time	s	2
			Linear velocity	m/min	15
Bonding pressure	kgf	4 (0.08 kgf/cm2)
			Coating weight	g/m	3+/-0.09

In various embodiments, adhesives containing the copolymers of the present invention do not exhibit a significant change in color when subjected to storage conditions at elevated temperatures for extended periods of time. The adhesive may have an initial gardner color of less than 18, 15, 10, 8, 5, 4, 3, 2, or 1 as measured according to ASTM D1544 before any aging due to storage occurs. After heat aging at 177 ℃ for at least 96 hours, the adhesive can exhibit a final gardner color of less than 18, 15, 10, 7, 5, 3, 2, or 1 as measured according to ASTM D1544. Thus, the adhesive can maintain a desirable color even after prolonged storage and exposure.

In another embodiment of the invention, the low molecular weight propylene-ethylene copolymer may be used in the adhesive compositions previously described in this disclosure, particularly, the low molecular weight copolymer may be used in the manufacture of hot melt adhesives having a wide process window and high peel strength (including destructive bonding to a substrate) for laminates (such as, but not limited to, sanitary products.) the adhesive composition containing the low molecular weight copolymer may be applied at an add-on ratio of about 0.5 gsm to about 5 gsm and suitable for creating laminates having a desired bond strength the peel strength created using the formulation of the invention may be from about 20 g/25 mm (~ 1 g/mm) to about 400 g/25 mm (16 g/mm) and to create a substrate destructive bond strength, in other embodiments the peel strength may be at least 20 g/25 mm, 30 g/25 mm, 40 g/25 mm, 50 g/25 mm, 60 g/25 mm, 70 g/25 mm, 80 g/25 mm, 90 g/25 mm or more, and optionally the hot melt adhesive may be used in various embodiments of the invention with a low adhesive weight of the present invention, the adhesive composition, the present invention may include at least one of the adhesive composition having a low peel strength of about 25 g/25 mm, 25 g/25 mm, 25 g/25 mm, 25 g/25 mm, 25 g/25 mm, 25 g/25 mm, 25 g/25 mm, 25 g/25 mm, 25 g/25 mm.

The invention may be further illustrated by the following examples of embodiments of the invention, although it will be understood that these examples are included merely for purposes of illustration and are not intended to limit the scope of the invention unless otherwise specifically indicated.

Examples