JPS63237207A - Production of perpendicular magnetic recording medium - Google Patents
Production of perpendicular magnetic recording mediumInfo
- Publication number
- JPS63237207A JPS63237207A JP6810087A JP6810087A JPS63237207A JP S63237207 A JPS63237207 A JP S63237207A JP 6810087 A JP6810087 A JP 6810087A JP 6810087 A JP6810087 A JP 6810087A JP S63237207 A JPS63237207 A JP S63237207A
- Authority
- JP
- Japan
- Prior art keywords
- carbon
- sputtering
- film
- magnetic recording
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 21
- 238000004544 sputter deposition Methods 0.000 claims abstract description 21
- 239000000758 substrate Substances 0.000 claims abstract description 17
- 238000000034 method Methods 0.000 claims abstract description 14
- 229910001339 C alloy Inorganic materials 0.000 claims abstract description 10
- 229910052751 metal Inorganic materials 0.000 claims abstract description 9
- 239000002184 metal Substances 0.000 claims abstract description 9
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 9
- 229920000642 polymer Polymers 0.000 claims abstract description 8
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 7
- 239000000463 material Substances 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 abstract description 4
- 239000000956 alloy Substances 0.000 abstract description 4
- 239000002131 composite material Substances 0.000 abstract description 4
- 230000007423 decrease Effects 0.000 abstract description 4
- 238000000465 moulding Methods 0.000 abstract 3
- 239000010408 film Substances 0.000 description 16
- 239000010409 thin film Substances 0.000 description 8
- 239000011651 chromium Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 5
- 229920001721 polyimide Polymers 0.000 description 5
- 239000011241 protective layer Substances 0.000 description 5
- 239000007789 gas Substances 0.000 description 4
- 239000004642 Polyimide Substances 0.000 description 3
- 239000006229 carbon black Substances 0.000 description 3
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 3
- 238000005477 sputtering target Methods 0.000 description 3
- 229910000599 Cr alloy Inorganic materials 0.000 description 2
- 229910001080 W alloy Inorganic materials 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910002059 quaternary alloy Inorganic materials 0.000 description 2
- 238000001004 secondary ion mass spectrometry Methods 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- CAVCGVPGBKGDTG-UHFFFAOYSA-N alumanylidynemethyl(alumanylidynemethylalumanylidenemethylidene)alumane Chemical compound [Al]#C[Al]=C=[Al]C#[Al] CAVCGVPGBKGDTG-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 150000001722 carbon compounds Chemical class 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- UFGZSIPAQKLCGR-UHFFFAOYSA-N chromium carbide Chemical compound [Cr]#C[Cr]C#[Cr] UFGZSIPAQKLCGR-UHFFFAOYSA-N 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 150000004985 diamines Chemical class 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229910003470 tongbaite Inorganic materials 0.000 description 1
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- -1 zircotium carbide Chemical compound 0.000 description 1
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Magnetic Record Carriers (AREA)
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は耐摩耗性に優れたＣｏ−Ｃｒ−Ｗ−Ｃ合金膜か
らなる垂直磁気記録媒体の製造方法に関するものである
。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a perpendicular magnetic recording medium made of a Co--Cr--W--C alloy film having excellent wear resistance.
高密度磁気記録媒体として、Ｃｏ−Ｃｒ系合金をスパッ
タリングした垂直磁気記録媒体が優れていることが知ら
れている。しかし、磁気記録媒体としてＣｏ−Ｃｒ系合
金層を使用した場合、磁気ヘッドとの摩擦抵抗が大きい
ため、摩耗や損傷を受は易く、耐久性に欠けるという問
題点がある。It is known that perpendicular magnetic recording media made of sputtered Co-Cr alloys are excellent as high-density magnetic recording media. However, when a Co--Cr alloy layer is used as a magnetic recording medium, there is a problem that it has a large frictional resistance with a magnetic head, is easily subject to wear and damage, and lacks durability.
このため、磁性金属薄膜上に耐摩耗性又は潤滑性の保護
層を設けることが考えられ、有機高分子、耐蝕性金属、
金属酸化物等の材料が試みられている。しかし、垂直磁
気記録が必要とされる高密度記録では、保護層の厚さが
問題となる。For this reason, it is possible to provide a wear-resistant or lubricating protective layer on the magnetic metal thin film.
Materials such as metal oxides have been tried. However, in high-density recording that requires perpendicular magnetic recording, the thickness of the protective layer becomes a problem.
すなわち、保護層を設けるとヘッドと媒体とのスペーシ
ングが拡がり、出力が低下する。このため、保護層の厚
みは高々５００Å以下で、スペーシング損失をな（すた
めには３０人程度以下にする必要がある。耐摩耗性の点
からは保護層の厚みは十分厚い必要があり、このような
厚さで耐摩耗性を十分改善することは極めて困難である
。このような問題を解決するためには磁化膜自体の耐摩
耗性を向上させることが必要である。その一方法として
Ｃ０１ＣｒＳＷ及びＣから成る合金の薄膜を磁化膜とし
て用いることが行われている。That is, when a protective layer is provided, the spacing between the head and the medium increases, resulting in a decrease in output. Therefore, the thickness of the protective layer must be at most 500 Å or less, and in order to avoid spacing loss, it is necessary to limit the number of people to approximately 30 or less.From the viewpoint of wear resistance, the thickness of the protective layer must be sufficiently thick. It is extremely difficult to sufficiently improve the wear resistance with such a thickness.To solve this problem, it is necessary to improve the wear resistance of the magnetized film itself.One way to do this is to improve the wear resistance of the magnetic film itself. As a method, a thin film of an alloy consisting of C01CrSW and C is used as a magnetization film.
この合金薄膜をスパッタリング法により作製する方法と
して、（１）Ｃｏ−Ｃｒ −Ｗ−Ｃの４元合金から成る
スパッタリングターゲットを作製してスパッタリングを
行うか、あるいは、（２）各元素のり−ゲットを組み合
わせたいわゆる複合ターゲツト法によりスパッタリング
を行うことが考えられる。Methods for producing this alloy thin film by sputtering include (1) producing a sputtering target made of a quaternary alloy of Co-Cr-W-C and performing sputtering, or (2) sputtering a sputtering target of each element. It is conceivable to perform sputtering by a combination of so-called composite target methods.
上記方法においては特に炭素の含ｆ量が重要であり、生
成する薄膜の物性は膜中の炭素含有量により微妙に影響
される。従って、上記スパッタリングにおいて炭素量を
制御することが必要である。In the above method, the carbon content is particularly important, and the physical properties of the formed thin film are subtly influenced by the carbon content in the film. Therefore, it is necessary to control the amount of carbon in the sputtering.
すなわち、前記（１）の合金ターゲツト法においては炭
素含有量を厳密に規定したＣｏ−Ｃｒ−Ｗ−Ｃの４元合
金ターゲツトを作製するという精密で煩雑な作業が必要
となる。また、（２）の複合ターゲツト法では炭素を均
一に膜中に混入することが難しいという問題が発生する
。さらに炭素の混入法としては、スパッタリングガス中
に炭素化合物のガスを混入する方法も考えられるが、炭
素以外に水素又は酸素等の元素が混入するため、良好な
膜は得られにくい。That is, the alloy target method (1) requires the precise and complicated work of producing a Co--Cr--W--C quaternary alloy target whose carbon content is strictly defined. Further, in the composite target method (2), a problem arises in that it is difficult to uniformly mix carbon into the film. Furthermore, as a method of mixing carbon, a method of mixing a carbon compound gas into the sputtering gas can be considered, but since elements such as hydrogen or oxygen are mixed in with the sputtering gas, it is difficult to obtain a good film.
本発明はこのような問題点を解決するもので、炭素又は
金属炭化物を含有する高分子成形物の基板上にＣｏ、Ｃ
ｒ及びＷをスパッタリングすることを特徴とするＣｏ−
Ｃｒ−Ｗ−Ｃ合金膜からなる垂直磁気記録媒体の製造方
法に関するものである。The present invention is intended to solve these problems, and it is possible to deposit Co, C, etc. on a substrate of a polymer molded product containing carbon or metal carbide.
Co- characterized by sputtering r and W
The present invention relates to a method of manufacturing a perpendicular magnetic recording medium made of a Cr--W--C alloy film.
本発明のスパッタリング法としては、炭素又は金属炭化
物を含有する高分子成形物の基板上に、複合ターゲツト
法によりＣｏ、Ｃｒ及びＷを同時にスパッタリングして
もよいし、またＣｏ−Ｃｒ−Ｗの合金ターゲットを使用
してスパッタリングしてもよい。In the sputtering method of the present invention, Co, Cr and W may be simultaneously sputtered onto a substrate of a polymer molded material containing carbon or metal carbide by a composite target method, or a Co-Cr-W alloy may be sputtered. Sputtering may also be performed using a target.
本発明の方法によれば、磁化膜中に微量の炭素を安定的
に混入することにより、耐摩耗性に優れた垂直磁気記録
媒体を得ることができる。スパッタリング法はプラズマ
雰囲気中でターゲット原子がスパッタされることにより
基板上に薄膜が形成されるが、その際基板表面も原子の
衝撃を受け、ある程度スパッタされるのと同様な現象が
起こると考えられる。本発明はこの現象を利用するもの
で、基板中に混入した炭素又は炭化物がスパッタされる
ことにより、磁化膜中に炭素が混入されることを特徴と
する。According to the method of the present invention, a perpendicular magnetic recording medium with excellent wear resistance can be obtained by stably incorporating a small amount of carbon into the magnetized film. In the sputtering method, a thin film is formed on a substrate by sputtering target atoms in a plasma atmosphere. At this time, the surface of the substrate is also bombarded by atoms, and it is thought that a phenomenon similar to sputtering occurs to some extent. . The present invention utilizes this phenomenon, and is characterized in that carbon or carbide mixed into the substrate is sputtered to mix carbon into the magnetized film.
本発明で使用される炭素としてはカーボンブラック、グ
ラファイト、また金属炭化物としては、炭化チタン、炭
化ケイ素、炭化アルミニウム、炭化ジルコチウム、炭化
クロム、炭化タングステン、炭化鉄等を挙げることがで
きる。その形状は粉末が最も好ましいが、他の形状であ
ってもかまわない。金属炭化物の使用量は、高分子成形
物に対して１〜２０ｗｔ％が好適である。Examples of carbon used in the present invention include carbon black and graphite, and examples of metal carbides include titanium carbide, silicon carbide, aluminum carbide, zircotium carbide, chromium carbide, tungsten carbide, and iron carbide. The most preferable shape is powder, but other shapes are also possible. The amount of metal carbide used is preferably 1 to 20 wt% based on the polymer molded product.
本発明で使用される高分子成形物としては、ポリイミド
、ポリエステル等を挙げることができる。Examples of the polymer molded product used in the present invention include polyimide and polyester.
Ｃｏ−Ｃｒ、−Ｗ−Ｃ合金膜の組成は、好ましくはＣｏ
含有量が５０〜８４原子％、Ｃｒ含有量が１５〜３５原
子％、Ｗ含有量が１〜１０原子％、Ｃ含有量が０．１〜
５原子％である。The composition of the Co-Cr, -W-C alloy film is preferably Co
The content is 50 to 84 at%, the Cr content is 15 to 35 at%, the W content is 1 to 10 at%, and the C content is 0.1 to 35 at%.
It is 5 atom%.
以下に実施例及び比較例を示し、本発明を更に詳しく説
明する。EXAMPLES The present invention will be explained in more detail by showing Examples and Comparative Examples below.
実施例１
ジカルボン酸無水物とジアミンとからなるポリイミドモ
ノマー溶液に平均粒径０．０３μｍのカーボンブラック
粉末を５ｗｔ％混入し、ガラス基板上に流延したのちイ
ミド化反応を行い、厚さ約５０μｍのポリイミドフィル
ムを作成した。これを基板とし、その表面に下記のスパ
ッタリング条件でスパッタし、厚さ約０．３ ｐ ｍの
Ｇｏ−Ｃｒ−Ｗ−Ｃ合金の薄膜Ａ（Ｃｒ含有量２８原子
％、Ｗ含有量２原子％、Ｃ含有量２．０原子％、残りＣ
ｏ）を形成した。Example 1 5 wt % of carbon black powder with an average particle size of 0.03 μm was mixed into a polyimide monomer solution consisting of dicarboxylic acid anhydride and diamine, and after casting on a glass substrate, an imidization reaction was performed to form a solution with a thickness of about 50 μm. A polyimide film was created. Using this as a substrate, a thin film A of Go-Cr-W-C alloy (Cr content: 28 atomic %, W content: 2 atomic %) having a thickness of approximately 0.3 pm was sputtered on its surface under the following sputtering conditions. , C content 2.0 at%, remaining C
o) was formed.
スパッタリング条件
装 置 マグネトロン式高周波スパッタリング
装置（二極平行平板型）
ターゲット Ｃｏ−Ｃｒ−Ｗ合金（２８原子％Ｃｒ
、２原子％Ｗ）
直径６インチ 厚さ５薗
スパッタガス Ａｒ 圧力０．５ Ｐ ａ基板の前
処理 真空中３８０″Ｃで２時間スパッタ電力 １
．５ｋＶ ６０ｍ１ｎスパツタ基板温度 水冷
実施例２
実施例１で用いたポリイミドモノマー溶液に平均粒径０
．０５μｍの炭化ケイ素粉末を５ｗｔ％混入し、実施例
１と同様にしてポリイミドフィルムを作成した。これを
基板とし、実施例１と同様にして厚さ０．３μｍの薄膜
Ｂ （Ｃｒ含有量２８原子％、Ｗ含有量２原子％、Ｃ含
有量１．５原子％、残りＣｏ）を作成した。Sputtering condition equipment Magnetron type high frequency sputtering equipment (two-pole parallel plate type) Target Co-Cr-W alloy (28 atomic% Cr
, 2 atomic% W) Diameter 6 inches Thickness 5 mm Sputtering gas Ar Pressure 0.5 Pa Pretreatment of a substrate Sputtering power 1 at 380''C in vacuum for 2 hours
．． 5kV 60m1n sputtering substrate temperature Water cooling Example 2 The polyimide monomer solution used in Example 1 had an average particle size of 0.
．． A polyimide film was prepared in the same manner as in Example 1 except that 5 wt % of silicon carbide powder with a diameter of 0.05 μm was mixed therein. Using this as a substrate, a 0.3 μm thick thin film B (Cr content: 28 at%, W content: 2 at%, C content: 1.5 at%, remainder Co) was created in the same manner as in Example 1. .
比較例１
カーボンブラック粉末を混入しなかった以外は、実施例
１と同様な方法により厚さ約０．３μｍの薄膜Ｃ（Ｃｏ
含有量７０原子％、Ｃｒ含有量２８原子％、Ｗ含有量２
原子％）を形成した。Comparative Example 1 A thin film C (Co
Content 70 at%, Cr content 28 at%, W content 2
%) was formed.
実施例１、実施例２及び比較例１で得られた各磁化膜中
の炭素の分布状態を二次イオン質量分析により分析した
結果を第１図に示す。カーボンブラック及び炭化ケイ素
入り基板の場合、磁化膜中の基板付近には基板内と同程
度の量の炭素が存在し、その量は表面に近づくにつれて
次第に減少するが、表面付近まで分布しており、Ｃｏ−
Ｃｒ−Ｗ−Ｃ合金が生成していることがわかる。FIG. 1 shows the results of analyzing the carbon distribution state in each magnetized film obtained in Example 1, Example 2, and Comparative Example 1 by secondary ion mass spectrometry. In the case of a substrate containing carbon black and silicon carbide, the amount of carbon in the magnetized film near the substrate is similar to that in the substrate, and the amount gradually decreases as it approaches the surface, but it is distributed near the surface. , Co-
It can be seen that a Cr-W-C alloy is produced.
上記の試料を５．２５インチのフロッピーディスクに加
工し、フロッピーディスク試験装置にかけＶＴＲ用リン
グヘッドを接触させたときの出力の変化を第２図に示す
。Ｃｏ−Ｃｒ−Ｗ−Ｃ合金の生成により出力低下が小さ
くなっており、耐摩耗性に優れていることがわかる。The above sample was processed into a 5.25-inch floppy disk, and FIG. 2 shows the change in output when it was placed in a floppy disk tester and brought into contact with a VTR ring head. It can be seen that the output decrease is small due to the formation of the Co-Cr-W-C alloy, and the wear resistance is excellent.
〔発明の効果］
本発明の方法によれば、磁化膜中に微量の炭素を安定的
にしかも簡便に混入した、耐摩耗性に優れた垂直磁気記
録媒体を得ることができる。[Effects of the Invention] According to the method of the present invention, it is possible to obtain a perpendicular magnetic recording medium with excellent wear resistance in which a trace amount of carbon is stably and simply mixed into the magnetized film.
第１図は実施例１、実施例２及び比較例１で得られた各
磁化膜中の炭素の分布状態を二次イオン質量分析法によ
り分析した結果を示す図である。
第２図は実施例１、実施例２及び比較例１で得られた各
磁化膜を５．２５インチのフロッピーディスクに加工し
、フロッピーディスク試験装置にかけＶＴＲ用リングヘ
ッドを接触させたときの出力の変化を示す図である。
第 １ 図
１許
町
エツチング“”吟Ｆ、”ｌ＋（ネダジ
第２図FIG. 1 is a diagram showing the results of analyzing the carbon distribution state in each magnetized film obtained in Example 1, Example 2, and Comparative Example 1 by secondary ion mass spectrometry. Figure 2 shows the output when each magnetized film obtained in Example 1, Example 2, and Comparative Example 1 was processed into a 5.25-inch floppy disk, and the floppy disk was placed in a floppy disk tester and a VTR ring head was brought into contact with it. FIG. Fig. 1 Kyocho etching “” Gin F, “l + (Nedaji Fig. 2
Claims (1)
Ｃｏ、Ｃｒ及びＷをスパッタリングすることを特徴とす
るＣｏ−Ｃｒ−Ｗ−Ｃ合金膜からなる垂直磁気記録媒体
の製造方法A method for manufacturing a perpendicular magnetic recording medium made of a Co-Cr-W-C alloy film, which comprises sputtering Co, Cr and W onto a substrate of a polymer molded material containing carbon or metal carbide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6810087A JPS63237207A (en) | 1987-03-24 | 1987-03-24 | Production of perpendicular magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6810087A JPS63237207A (en) | 1987-03-24 | 1987-03-24 | Production of perpendicular magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63237207A true JPS63237207A (en) | 1988-10-03 |
Family
ID=13363983
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6810087A Pending JPS63237207A (en) | 1987-03-24 | 1987-03-24 | Production of perpendicular magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63237207A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02141920A (en) * | 1988-11-22 | 1990-05-31 | Matsushita Electric Ind Co Ltd | Magnetic recording medium |
| WO2006055198A1 (en) | 2004-11-12 | 2006-05-26 | Eastman Chemical Company | Polyester polymer and copolymer compositions containing titanium carbide particles |
| US8987408B2 (en) | 2005-06-16 | 2015-03-24 | Grupo Petrotemex, S.A. De C.V. | High intrinsic viscosity melt phase polyester polymers with acceptable acetaldehyde generation rates |
-
1987
- 1987-03-24 JP JP6810087A patent/JPS63237207A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02141920A (en) * | 1988-11-22 | 1990-05-31 | Matsushita Electric Ind Co Ltd | Magnetic recording medium |
| WO2006055198A1 (en) | 2004-11-12 | 2006-05-26 | Eastman Chemical Company | Polyester polymer and copolymer compositions containing titanium carbide particles |
| JP2008519883A (en) * | 2004-11-12 | 2008-06-12 | イーストマン ケミカル カンパニー | Polyester polymer and copolymer compositions comprising titanium carbide particles |
| US8987408B2 (en) | 2005-06-16 | 2015-03-24 | Grupo Petrotemex, S.A. De C.V. | High intrinsic viscosity melt phase polyester polymers with acceptable acetaldehyde generation rates |
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