A polyimide profile and a method for producing the same

Abstract

The application provides a polyimide profile and a preparation method thereof, and comprises the following steps: adding polyimide resin powder into a mold of a molding machine and keeping the polyimide resin powder at a preheating temperature; the preheating temperature is 200-230 DEG C; putting an upper pressing plate of the mold into the mold, and performing stage-by-stage pressing on the polyimide resin powder; keeping pressure for 3-5 s after each stage of pressing; the pressure of stage-by-stage pressing is adjusted from low to high; the stage-by-stage pressing process is repeated for multiple times; keeping pressure on the polyimide resin powder under the molding pressure, and simultaneously heating the mold to a molding temperature, so that the polyimide resin powder is kept at the molding temperature and the molding pressure; after the keeping pressure process is completed, cooling and demolding are performed, and thus the polyimide profile is obtained. The preheating temperature of the polyimide resin powder in the mold of the molding machine is controlled, and the polyimide resin powder in the mold is subjected to stage-by-stage pressing operation before the mold is heated to the molding temperature, so that the polyimide resin is completely plasticized and exhausts completely, the polyimide profile prepared has uniform appearance color, the impact strength is 280 kJ / m 2 The performance is better.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polymer material forming, more particularly, to a polyimide profile and a preparation method thereof. BACKGROUND

[0002] Polyimide resin is widely used in aerospace components, semiconductor processing, automobile manufacturing and energy production, etc. demanding harsh electrical insulation, thermal insulation and wear-resistant fields due to its excellent temperature resistance, insulation and mechanical properties.

[0003] Polyimide profiles are generally prepared by molding, but conventional molding processes usually result in incomplete plasticization of polyimide profiles, uneven color on the surface of the profile, and low mechanical properties. SUMMARY

[0004] In view of the defects of the existing molding process, such as incomplete exhaust, incomplete plasticization, uneven surface of the profile, and low material performance during the molding process, the present application aims to provide a polyimide profile and a preparation method thereof. The method optimizes the exhaust process and solves the problems of incomplete exhaust, uneven color and low performance of the material. The polyimide profile prepared by the present application has uniform appearance color and better performance.

[0005] To achieve the above-mentioned purpose, the first aspect of the present application provides a preparation method of a polyimide profile, comprising the following steps:

[0006] The polyimide resin powder is added to the mold of the molding machine and is kept at a preheating temperature; the preheating temperature is 200-230℃;

[0007] The upper platen of the mold is placed in the mold, and the polyimide resin powder is subjected to staged pressing, with 3-5s holding pressure after each stage of pressing, and the pressure of the staged pressing is adjusted from low to high, and the staged pressing process is repeated multiple times;

[0008] The polyimide resin powder is subjected to holding pressure under the molding pressure, and the mold is heated to the molding temperature, so that the polyimide resin powder is subjected to holding pressure and temperature treatment at the molding temperature and the molding pressure;

[0009] After the holding pressure and temperature treatment is completed, the temperature is lowered and the mold is demolded, and a polyimide profile is obtained.

[0010] Further, the staged pressing comprises the following steps:

[0011] The pressure is raised from 0 to a first pressure, and pressure is maintained for 3-5s; then raised to a second pressure, and pressure is maintained for 3-5s; then raised to a third pressure, and pressure is maintained for 3-5s, then raised to a fourth pressure, and pressure is maintained for 3-5s; finally raised to a fifth pressure, and pressure is maintained for 3-5s.

[0012] Further, the pressure difference between two adjacent stages is 25-35kg / cm 2 .

[0013] Further, the fifth pressure is 150-160kg / cm 2 .

[0014] Further, the step-by-step pressure process is repeated for 8-12 times.

[0015] Further, the mold pressing pressure is 50-70kg / cm 2 .

[0016] Further, the mold pressing temperature is 360-390℃.

[0017] Further, the holding pressure treatment time is 30-50min.

[0018] Further, the cooling temperature when demolding is 200-230℃.

[0019] In the second aspect of the present application, a polyimide profile is provided, which is prepared by the preparation method of any one of the above.

[0020] Compared with the prior art, the present application has the following technical effects:

[0021] The preparation method of the polyimide profile of the present application controls the preheating temperature of the polyimide resin powder in the mold of the mold pressing machine, and performs a step-by-step pressure operation on the polyimide resin powder in the mold before the mold is heated to the mold pressing temperature, so that the polyimide resin is completely plasticized and exhausts completely, and the prepared polyimide profile has uniform appearance color and impact strength of 280kJ / m 2 The above, the performance is better.

[0022] The polyimide profile prepared by the present application has uniform appearance color and impact strength of 280kJ / m2 or more. DETAILED DESCRIPTION

[0023] In order to make the technical problems to be solved by the present application, the technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0024] The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0025] The weight of the related components mentioned in the specification of the embodiments of the application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of each component. Therefore, as long as the content of the related components in the specification of the embodiments of the application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the application. Specifically, the mass mentioned in the specification of the embodiments of the application can be μg, mg, g, kg and other mass units commonly known in the biochemical field.

[0026] The terms "first", "second", "third" and the like in the description of the application do not denote any quantity or order, but are used only for the purpose of description, to distinguish one element from another. For example, a first XX can also be referred to as a second XX, and similarly, a second XX can also be referred to as a first XX, without departing from the scope of the embodiments of the application. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0027] The embodiments of the application provide a polyimide profile and a preparation method thereof, which comprises the following steps:

[0028] (1) polyimide resin powder is added to the mold of the molding machine, and the polyimide resin powder is kept at a preheating temperature; the preheating temperature is 200-230℃;

[0029] (2) the upper platen of the mold is put into the mold, and the polyimide resin powder is subjected to stage-by-stage pressing, each stage of pressing is kept for 3-5s after completion of pressing, and the pressure of stage-by-stage pressing is adjusted from low to high, and the stage-by-stage pressing process is repeated multiple times;

[0030] (3) the polyimide resin powder is kept at a molding pressure, and the mold is heated to a molding temperature, so that the polyimide resin powder is kept at the molding temperature and the molding pressure for heat preservation and pressure retention treatment;

[0031] (4) after the heat preservation and pressure retention treatment is completed, the temperature is lowered and the mold is demolded, and a polyimide profile is obtained.

[0032] In the step (1) above, the preheating temperature of the polyimide resin powder is controlled to 200-230 DEG C in the embodiment of the present application, so that the polyimide resin powder can still keep in powder state in the subsequent stage pressing process, so that the gas in the polyimide resin powder can be better discharged by the stage pressing, avoiding that the partial polyimide resin powder is plasticized due to the too high preheating temperature, causing difficult or incomplete exhaust in the subsequent process, and affecting the performance of the prepared polyimide profile.

[0033] Specifically, the mold cavity specification of the embodiment of the present application is 100x100x60mm, the mold pressing machine is a 200T oil pressure forming machine, the release agent is a high temperature release agent, and the polyimide resin powder is YS20.

[0034] In the step (2) above, the stage pressing is adopted and the holding time of each stage is controlled to discharge the gas in the polyimide resin powder in the embodiment of the present application, so that the gas in the polyimide resin powder can be better discharged, and the performance of the prepared polyimide profile is improved. The gas in the polyimide resin powder cannot be sufficiently discharged by the conventional one-stage or two-stage exhaust, resulting in that the prepared polyimide profile is yellow and opaque, and the impact strength is also low.

[0035] Further, the stage pressing of the embodiment of the present application comprises the following steps:

[0036] The pressure is increased from 0 to the first pressure, and held for 3-5s; then increased to the second pressure, and held for 3-5s; then increased to the third pressure, and held for 3-5s, then increased to the fourth pressure, and held for 3-5s; finally increased to the fifth pressure, and held for 3-5s. Preferably, the pressure difference between adjacent two stages is 25-35kg / cm 2 , specifically, the pressure starts from 0, and each 30kg / cm 2 is an increase stage.

[0037] In the embodiment of the present application, the fifth pressure is 150-160kg / cm 2 , that is, the maximum pressure of the increase is 150-160kg / cm 2 .

[0038] In the embodiment of the present application, the stage pressing process is repeated for 8-12 times, so that good exhaust effect can be obtained, and the polyimide profile with uniform appearance and good impact strength performance can be prepared.

[0039] In the step (3) above, the mold pressing pressure of the embodiment of the present application is 50-70kg / cm 2 , the mold pressing temperature is 360-390 DEG C, and the holding time of the holding and pressure treatment is 30-50min.

[0040] In step (4) above, the temperature of the present embodiment during the cooling demolding is 200-230°C.

[0041] The method for preparing the polyimide profile of the present embodiment controls the preheating temperature of the polyimide resin powder in the mold of the molding machine, and performs a staged pressure operation on the polyimide resin powder in the mold before the mold is heated to the molding temperature, so that the polyimide resin is completely plasticized and exhausts completely. The prepared polyimide profile has uniform appearance color, impact strength of 280kJ / m 2 The performance is better.

[0042] The polyimide profile and the method for preparing the same of the present embodiment are illustrated by a plurality of specific embodiments.

[0043] Embodiment 1

[0044] The present embodiment 1 provides a polyimide profile and a method for preparing the same, which comprises the following steps:

[0045] The mold is placed on the heating platform of the molding machine, the preheating temperature is set to 200°C, the temperature is raised, after reaching the preheating temperature, the mold release agent is coated, then 55.2g of YS20 polyimide resin powder is added, and the temperature is kept for 30min at the preheating temperature. After the temperature keeping is completed, the upper platen of the mold is placed in the mold cavity, then the pressure is raised to 30kg / cm 2 , stays for 5s; then the pressure is raised to 60kg / cm 2 , stays for 5s; the pressure is raised to 90kg / cm 2 , stays for 5s; the pressure is raised to 120kg / cm 2 , stays for 5s; the pressure is raised to 150kg / cm 2 , stays for 5s; then the pressure is released and the above staged pressure raising step is repeated, a total of 10 times, then the molding pressure is set to 50kg / cm 2 , and the pressure is kept, at the same time, the molding temperature is set to 380°C, the temperature is raised, after reaching the molding temperature, the temperature is kept for 40min, after the temperature keeping and pressure keeping are completed, the temperature is cooled to 200°C by air cooling, and the mold is demolded.

[0046] Embodiment 2

[0047] The present embodiment 2 provides a polyimide profile and a method for preparing the same, which comprises the following steps:

[0048] The mold is placed on the heating platform of the molding machine, the preheating temperature is set to 200°C, the temperature is raised, after reaching the preheating temperature, the mold release agent is coated, then 55.2g of YS20 polyimide resin powder is added, and the temperature is kept for 30min at the preheating temperature. After the temperature keeping is completed, the upper platen of the mold is placed in the mold cavity, then the pressure is raised to 30kg / cm 2, stay 5s; then the pressure is raised to 60kg / cm 2 , stay 5s; the pressure is raised to 90kg / cm 2 , stay 5s; the pressure is raised to 120kg / cm 2 , stay 5s; the pressure is raised to 150kg / cm 2 , stay 5s; then the pressure is unloaded and the above-mentioned step of raising the pressure in stages is repeated for a total of 10 times, then the mould pressing pressure is set to 60kg / cm 2 , and pressure is maintained, while the mould pressing temperature is set to 390℃, temperature is raised, after reaching the mould pressing temperature, temperature is maintained and pressure is maintained for 50min, after the temperature maintaining and pressure maintaining is finished, air cooling is performed to reduce the temperature to 220℃, then the mould is demoulded.

[0049] Example 3

[0050] The polyimide profile and the preparation method thereof provided by the embodiment 3 of the present application comprise the following steps:

[0051] The mould is placed on the heating platform of the mould pressing machine, the preheating temperature is set to 220℃, temperature is raised, after reaching the preheating temperature, the mould releasing agent is coated, then 55.2g of YS20 polyimide resin powder is added, temperature is maintained for 30min at the preheating temperature, after the temperature maintaining is finished, the upper pressing plate of the mould is placed in the mould cavity, then the pressure is raised to 30kg / cm 2 , stay 5s; then the pressure is raised to 60kg / cm 2 , stay 5s; the pressure is raised to 90kg / cm 2 , stay 5s; the pressure is raised to 120kg / cm 2 , stay 5s; the pressure is raised to 150kg / cm 2 , stay 5s; then the pressure is unloaded and the above-mentioned step of raising the pressure in stages is repeated for a total of 9 times, then the mould pressing pressure is set to 70kg / cm 2 , and pressure is maintained, while the mould pressing temperature is set to 370℃, temperature is raised, after reaching the mould pressing temperature, temperature is maintained and pressure is maintained for 30min, after the temperature maintaining and pressure maintaining is finished, air cooling is performed to reduce the temperature to 200℃, then the mould is demoulded.

[0052] Example 4

[0053] The polyimide profile and the preparation method thereof provided by the embodiment 4 of the present application comprise the following steps:

[0054] The mould is placed on the heating platform of the mould pressing machine, the preheating temperature is set to 230℃, temperature is raised, after reaching the preheating temperature, the mould releasing agent is coated, then 55.2g of YS20 polyimide resin powder is added, temperature is maintained for 30min at the preheating temperature, after the temperature maintaining is finished, the upper pressing plate of the mould is placed in the mould cavity, then the pressure is raised to 30kg / cm 2 , stay 5s; then the pressure is raised to 60kg / cm2 , stay 5s; the pressure is raised to 90kg / cm 2 , stay 5s; the pressure is raised to 120kg / cm 2 , stay 5s; the pressure is raised to 150kg / cm 2 , stay 5s; then the pressure is unloaded and the above-mentioned step of raising the pressure in stages is repeated for 12 times, and then the mould pressing pressure is set to 50kg / cm 2 , and pressure is kept, at the same time, the mould pressing temperature is set to 360℃, temperature is raised, after reaching the mould pressing temperature, temperature is kept for 50min, after the temperature keeping and pressure keeping is finished, air cooling is used to reduce the temperature to 210℃, and then the mould is demoulded.

[0055] Comparative Example 1

[0056] The present application provides a polyimide profile and a preparation method thereof, comprising the following steps:

[0057] The mould is placed on the heating platform of the mould pressing machine, the preheating temperature is set to 200℃, temperature is raised, after reaching the preheating temperature, the mould releasing agent is coated, then 55.2g of YS20 polyimide resin powder is added, temperature is kept for 30min at the preheating temperature, after the temperature keeping is finished, the upper pressing plate of the mould is placed in the mould cavity, then the pressure is raised to 30kg / cm 2 ; the pressure is raised to 60kg / cm 2 ; the pressure is raised to 90kg / cm 2 ; the pressure is raised to 150kg / cm 2 ; then the pressure is unloaded and the above-mentioned step of raising the pressure in stages is repeated for 10 times, and then the mould pressing pressure is set to 50kg / cm 2 , and pressure is kept, at the same time, the mould pressing temperature is set to 380℃, temperature is raised, after reaching the mould pressing temperature, temperature is kept for 40min, after the temperature keeping and pressure keeping is finished, air cooling is used to reduce the temperature to 200℃, and then the mould is demoulded.

[0058] Comparative Example 2

[0059] The present application provides a polyimide profile and a preparation method thereof, comprising the following steps:

[0060] The mould is placed on the heating platform of the mould pressing machine, the preheating temperature is set to 200℃, temperature is raised, after reaching the preheating temperature, the mould releasing agent is coated, then 55.2g of YS20 polyimide resin powder is added, temperature is kept for 30min at the preheating temperature, after the temperature keeping is finished, the upper pressing plate of the mould is placed in the mould cavity, then the pressure is raised to 30kg / cm 2 , stay 5s; the pressure is raised to 60kg / cm 2 , stay 5s; the pressure is raised to 90kg / cm 2 , stay 5s; the pressure is raised to 120kg / cm2 , stay for 5s; the pressure is raised to 150kg / cm 2 , stay for 5s; then the pressure is unloaded and the above-mentioned step of raising the pressure is repeated for 6 times, then the mold pressing pressure is set to 50kg / cm 2 , and the pressure is kept, at the same time, the mold pressing temperature is set to 380℃, the temperature is raised, after reaching the mold pressing temperature, the temperature is kept for 40min, after the temperature keeping, the temperature is cooled to 200℃ by air cooling, then the mold is demolded.

[0061] Comparative Example 3

[0062] The present application provides a polyimide profile and a preparation method thereof, comprising the following steps:

[0063] The mold is placed on the heating platform of the mold pressing machine, the preheating temperature is set to 200℃, the temperature is raised, after reaching the preheating temperature, the mold releasing agent is coated, then 55.2g of YS20 polyimide resin powder is added, the temperature is kept for 30min at the preheating temperature, after the temperature keeping, the upper pressing plate of the mold is placed in the mold cavity, at the same time, the mold pressing temperature is set to 380℃, the temperature is raised, after reaching the mold pressing temperature, the temperature is kept for 40min, after the temperature keeping, the temperature is cooled to 200℃ by air cooling, then the mold is demolded. 2 , stay for 25s; then the pressure is unloaded and the above-mentioned step of raising the pressure is repeated for 10 times, then the mold pressing pressure is set to 50kg / cm 2 , and the pressure is kept, at the same time, the mold pressing temperature is set to 380℃, the temperature is raised, after reaching the mold pressing temperature, the temperature is kept for 40min, after the temperature keeping, the temperature is cooled to 200℃ by air cooling, then the mold is demolded.

[0064] Comparative Example 4

[0065] The present application provides a polyimide profile and a preparation method thereof, comprising the following steps:

[0066] The mold is placed on the heating platform of the mold pressing machine, the preheating temperature is set to 200℃, the temperature is raised, after reaching the preheating temperature, the mold releasing agent is coated, then 55.2g of YS20 polyimide resin powder is added, the temperature is kept for 30min at the preheating temperature, after the temperature keeping, the upper pressing plate of the mold is placed in the mold cavity, at the same time, the mold pressing temperature is set to 380℃, the temperature is raised, after reaching the mold pressing temperature, the pressure is raised to 30kg / cm 2 , stay for 5s; then the pressure is raised to 60kg / cm 2 , stay for 5s; the pressure is raised to 90kg / cm 2 , stay for 5s; the pressure is raised to 120kg / cm 2 , stay for 5s; the pressure is raised to 150kg / cm 2 , stay for 5s; then the pressure is unloaded and the above-mentioned step of raising the pressure is repeated for 10 times, then the mold pressing pressure is set to 50kg / cm 2and pressure holding, and then wind cooling to 200℃ after 40 minutes of pressure holding and heat preservation, and the mold can be demolded.

[0067] Comparative Example 5

[0068] The present application provides a polyimide profile and a preparation method thereof, comprising the following steps:

[0069] The mold was placed on the heating platform of the molding machine, the preheating temperature was set to 200℃, and the temperature was raised. After reaching the preheating temperature, release agent was applied, and then 55.2g of YS20 polyimide resin powder was added. After 30 minutes of heat preservation at the preheating temperature, the upper platen of the mold was placed in the mold cavity, and then the pressure was increased to 60kg / cm 2 for 10s. Then the pressure was increased to 150kg / cm 2 for 15s. Then the pressure was released and the above two-stage pressure increasing steps were repeated for a total of 10 times. Then the molding pressure was set to 50kg / cm 2 , and pressure holding was performed, and the molding temperature was set to 380℃ at the same time. After reaching the molding temperature, 40 minutes of pressure holding and heat preservation were performed. After the end of pressure holding and heat preservation, wind cooling was performed to reduce the temperature to 200℃, and the mold could be demolded.

[0070] Comparative Example 6

[0071] The present application provides a polyimide profile and a preparation method thereof, comprising the following steps:

[0072] The mold was placed on the heating platform of the molding machine, the preheating temperature was set to 200℃, and the temperature was raised. After reaching the preheating temperature, release agent was applied, and then 55.2g of YS20 polyimide resin powder was added. After 30 minutes of heat preservation at the preheating temperature, the upper platen of the mold was placed in the mold cavity, and then the pressure was increased to 60kg / cm 2 for 10s. Then the pressure was increased to 90kg / cm 2 for 5s. Then the pressure was increased to 150kg / cm 2 for 10s. Then the pressure was released and the above three-stage pressure increasing steps were repeated for a total of 10 times. Then the molding pressure was set to 50kg / cm 2 , and pressure holding was performed, and the molding temperature was set to 380℃ at the same time. After reaching the molding temperature, 40 minutes of pressure holding and heat preservation were performed. After the end of pressure holding and heat preservation, wind cooling was performed to reduce the temperature to 200℃, and the mold could be demolded.

[0073] The polyimide profiles obtained in Examples 1-4 and Comparative Examples 1-6 were subjected to appearance inspection and impact strength test. The performance comparison is shown in Table 1.

[0074] Table 1

[0075] Appearance Impact strength (kJ / m 2 ) Example 1 Transparent, amber, uniform and consistent 285 Example 2 Transparent, amber, uniform and consistent 286 Example 3 Transparent, amber, uniform and consistent 289 Example 4 Transparent, amber, uniform and consistent 287 Comparative Example 1 Surface yellowing, not transparent 255 Comparative Example 2 Surface yellowing, not transparent 254 Comparative Example 3 Surface yellowing, not transparent 249 Comparative Example 4 Surface yellowing, not transparent 242 Comparative Example 5 Surface yellowing, not transparent 251 Comparative Example 6 Surface yellowing, not transparent 253

[0076] From the test results of Table 1, it can be seen that the preparation method of Examples 1-4 of the present application controls the preheating temperature of the polyimide resin powder in the mold of the molding machine, and performs a staged pressure operation on the polyimide resin powder in the mold before the mold is heated to the molding temperature, and controls the holding time of each stage, so that the polyimide resin is completely plasticized and exhausts completely, and the prepared polyimide profile has a transparent appearance and uniform amber color, and the impact strength is all above 280 kJ / m 2 Compared with the comparative examples, the impact strength can be increased by 19.4% at most.

[0077] The above examples only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for producing a polyimide profile, characterized by, The method comprises the following steps: adding polyimide resin powder into a mold of a molding machine and keeping the polyimide resin powder at a preheating temperature; the preheating temperature is 200-230 ℃; putting an upper pressing plate of the mold into the mold and performing stage-by-stage pressing on the polyimide resin powder, keeping pressure for 3-5 s after each stage of pressing, adjusting the pressure from low to high in the stage-by-stage pressing, and repeating the stage-by-stage pressing process for multiple times; keeping the polyimide resin powder at a molding pressure and heating the mold to a molding temperature, and keeping the polyimide resin powder at the molding temperature and the molding pressure for a holding and pressing treatment; after the holding and pressing treatment is completed, cooling and demolding to obtain a polyimide profile.

2. A method of producing a polyimide profile according to claim 1, characterized in that, The stage-by-stage pressing comprises the following steps: the pressure is increased from 0 to a first pressure, kept for 3-5 s, then increased to a second pressure, kept for 3-5 s, then increased to a third pressure, kept for 3-5 s, then increased to a fourth pressure, kept for 3-5 s, and finally increased to a fifth pressure, kept for 3-5 s.

3. A method of producing a polyimide profile according to claim 2, characterised in that, The pressure difference between two adjacent stages is 25-35 kg / cm 2 .

4. A method of making a polyimide profile according to claim 2, wherein The fifth pressure is 150-160 kg / cm 2 .

5. A method of making a polyimide profile according to claim 1, wherein, The stage-by-stage pressing process is repeated for 8-12 times.

6. A method of making a polyimide profile according to claim 1, wherein, The moulding pressure is 50-70 kg / cm 2 .

7. A method of making a polyimide profile according to claim 1, wherein, The molding temperature is 360-390 ℃.

8. A method of making a polyimide profile according to claim 1, wherein, The holding and pressing treatment is performed for 30-50 min.

9. A process for the production of a polyimide profile according to any one of claims 1 to 8, characterized in that, The cooling temperature during the cooling and demolding is 200-230 ℃.

10. A polyimide profile, characterized in that, The method is prepared by any one of claims 1-9.