JPH08300469A - Stretched film made of polycarbodiimide resin and production thereof - Google Patents

Abstract

PURPOSE: To obtain a polycarbodiimide resin stretched film thermally restorable to a state before stretching by uniaxially stretching a forming material based on a specific polycarbodiimide resin. CONSTITUTION: A polycarbodiimide film is obtained by uniaxially stretching a forming material based on a polycarbodiimide resin represented by formula I (X is -NCO, -NH2 or an aryl group, R is a group represented by either one of formulae II, III, R1 is a 1-5C aliphatic hydrocarbon group or an alkoxy group and n is an integer of 20-100) and has a thermal characteristic (A) wherein a glass transition temp. is 0-150 deg.C and a thermoplastic characteristic (B) wherein an m.p. is 200-230 deg.C. This film can be applied to a surface coating tube material or a bundling tape material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbodiimide resin stretched film which shrinks to a state before stretching by heating and a method for producing the same.

[0002]

2. Description of the Related Art Heretofore, those obtained by using a polycarbodiimide resin have been used in various fields. For example, flame-resistant films, raw materials for heat-resistant adhesives, and thermosetting films are known that utilize their heat resistance.

[0003]

However, these conventional films were simply formed into a film shape, and there was no film in which various properties other than the heat resistance of the polycarbodiimide resin itself were utilized.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a stretched film made of a polycarbodiimide resin, which is heat-shrinkable and can be heat-recovered to a state before stretching, and a manufacturing method thereof. .

[0005]

In order to achieve the above-mentioned object, the present invention provides a uniaxially stretched poly-containing material containing a polycarbodiimide resin represented by the following general formula (1) as a main component. The first gist is a carbodiimide resin film, which is a polycarbodiimide resin stretched film having the following thermal characteristics (A) and (B). (A) The glass transition temperature is in the range of 0 to 150 ° C. (B) The melting point is in the range of 200 to 230 ° C.

[0006]

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Further, a step of preparing an organic solvent solution containing a polycarbodiimide resin represented by the following general formula (1), and the organic solvent solution is subjected to the following (a) and (b):
The second gist is a method for producing a stretched film of a polycarbodiimide resin, which comprises a step of forming a film by coating and drying under a temperature condition satisfying the above condition, and a step of uniaxially stretching the film. (A) Glass transition temperature or higher of the polycarbodiimide resin contained in the organic solvent solution. (B) Below the melting point of the polycarbodiimide resin contained in the organic solvent solution.

[0008]

[Chemical 4]

[0009]

That is, the present invention uses an organic solvent solution containing the polycarbodiimide resin represented by the general formula (1) and has a glass transition temperature or higher and a melting point or lower, which are thermal characteristics of the polycarbodiimide resin. The coated film is dried under the temperature condition of 1 and stretched in a uniaxial direction to prepare a stretched film of polycarbodiimide resin. The stretched film made of a polycarbodiimide resin has thermal characteristics of a glass transition temperature (hereinafter referred to as “Tg”) of 0 to 150 ° C. and a melting point (hereinafter referred to as “Tm”) of 200 to 230 ° C. Therefore, this stretched film made of polycarbodiimide resin utilizes the property of recovering heat to the state before stretching by heating, and forms coatings, bindings, etc. in various fields such as tube materials for surface coating and binding tape materials. It can be applied to materials.

Next, the present invention will be described in detail.

The stretched film of polycarbodiimide resin of the present invention can be obtained by stretching treatment using a forming material containing a polycarbodiimide resin as a main component.

The polycarbodiimide resin is represented by the following general formula (1).

[0013]

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In the above equation (1), the number of repetitions n is n
= 20 to a positive number of 100, particularly preferably n = 40
Is a positive number from -80. That is, when the number of repetitions n is less than 20, the solution viscosity of the obtained polycarbodiimide resin film-forming material is low and it becomes difficult to form a film. On the other hand, when the number of repetitions n exceeds 100, the stability of the solution becomes poor and the handling becomes inconvenient.

R in the above formula (1) is determined by the kind of the monomer used for synthesizing the polycarbodiimide resin and becomes various substituted arylene groups. R in it
₁ is an aliphatic hydrocarbon group having 1 to 5 carbon atoms or an alkoxy group, and examples thereof include a methyl group, an ethyl group, an isopropyl group and a methoxy group. Furthermore, X polycarbodiimide resin both ends but may be -NCO, may be -NH ₂ is reacted with water. Further, monoisocyanate may be used as the aryl group, and examples thereof include those represented by the following formula (2).

[0016]

[Chemical 6]

In the formula (2), R ₂ is hydrogen, an alkyl group having 1 to 5 carbon atoms, —OCH ₃ , —OC ₂ H ₅ , or —O.
Examples include CH (CH ₃ ) ₂ and halogen. Among them, R ₂ is preferably an alkyl group having 1 to 5 carbon atoms from the viewpoint of increasing the solubility of the polymer and not lowering the heat resistance.

As described above, as the optimum combination of R and X in the formula (1), the following combinations can be given. That is, R is as shown below.

[0019]

[Chemical 7]

X is as shown below.

[0021]

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Such a polycarbodiimide resin can be obtained, for example, by a conventionally known production method. That is, the journal of Applied Polymer Science by LM Alberino et al. [J.ap.
pl. Polym. Sci., 21, PP1999 (1977)], JP-A-4-27.
The manufacturing method disclosed in Japanese Patent No. 5359 can be mentioned. This is a method for producing a polycarbodiimide resin by reacting an organic isocyanate in an organic solvent in the presence of a carbodiimidization catalyst.

The organic isocyanate may be either unmodified isocyanate or modified isocyanate. Further, all of mono-, di-, tri-, tetra-isocyanate and the like can be used. Further, a part of the organic isocyanate may be copolymerized with polyalkylene glycol such as polyethylene glycol and polytetramethylene glycol.

As the above-mentioned unmodified isocyanate, aliphatic isocyanate, alicyclic isocyanate, aromatic isocyanate, naphthalene isocyanate, biphenyl isocyanate, diphenyl isocyanate, triphenyl isocyanate, triisocyanate, tetraisocyanate, organic phosphorus isocyanate, fluorinated isocyanate, etc. Can be given.

Specific examples of the aliphatic isocyanate include straight chain aliphatic isocyanates such as ethane diisocyanate, propane diisocyanate and hexamethylene diisocyanate, 2,2-dimethylpentane diisocyanate and 2,2,4-trimethylpentane diisocyanate. And branched linear aliphatic isocyanates such as ω, ω′-dipropyl ether diisocyanate, thiodipropyl diisocyanate, and 1,4-butylene glycol dipropyl ether-ω, ω′-diisocyanate.

Examples of the alicyclic isocyanate include isophorone isocyanate, 4,4'-dicyclohexylmethane diisocyanate, trans-1,4-dicyclohexyl diisocyanate, and 1,2-dimethylcyclohexane-ω, ω'-diisocyanate.

As the above-mentioned aromatic isocyanate, paraphenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-
Methoxyphenyl-2,4-diisocyanate, diphenyl ether-4,4'-diisocyanate and the like can be mentioned.

As the naphthalene isocyanate,
Examples thereof include naphthalene-1,4-diisocyanate and 1,1'-dynephtyl-2,2'-diisocyanate.

As the above-mentioned biphenyl isocyanate,
Biphenyl-4,4'-diisocyanate, 3,3'-
Examples thereof include dimethyl biphenyl-4,4'-diisocyanate.

Examples of the diphenylmethane isocyanate include diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate and 3,3'-dimethyl-4,4'-.
Examples thereof include diphenylmethane diisocyanate.

Examples of the triisocyanate include 1-methylbenzene-2,4,6-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, triphenylmethane-4,4 ', 4 "-triisocyanate and the like. Can be given.

Examples of the above tetraisocyanate include dimethyltriphenylmethane tetraisocyanate.

Examples of the above organic phosphorus isocyanate include ethylphosphoryl bisisocyanate.

On the other hand, as the modified isocyanate,
Examples thereof include urethane-modified isocyanate, allophanate-modified isocyanate, burette-modified isocyanate, carbodiimide-modified isocyanate, and uretomine-modified isocyanate.

Specific examples of the urethane-modified isocyanate include those represented by the chemical formula (3) shown below.

[0036]

[Chemical 9]

Examples of the above allophanate-modified isocyanate include those represented by the chemical formula (4) shown below.

[0038]

[Chemical 10]

Examples of the burette-modified isocyanate include those represented by the chemical formula (5) shown below.

[0040]

[Chemical 11]

Examples of the carbodiimide-modified isocyanate include those represented by the chemical formula (6) shown below.

[0042]

[Chemical 12]

Examples of the uretomin-modified isocyanate include those represented by the chemical formula (7) shown below.

[0044]

[Chemical 13]

These organic isocyanates may be used alone or in combination of two or more.

As the carbodiimidization catalyst for reacting the above organic diisocyanate, 1-phenyl-2-phosphorene-1-oxide, 3-methyl-2-phosphorene-
1-oxide, 1-ethyl-2-phospholen-1-oxide, 1-ethyl-2-phospholen-1-oxide, 3
-Methyl-1-phenylphosphorene-1-oxide, or a phospholene oxide such as a 3-phospholene isomer thereof can be used. In particular, 3-methyl-1
Preference is given to using -phenylphosphorene-1-oxide.

As the organic solvent for reacting the above organic diisocyanate, conventionally known ones can be used. Specifically, tetrachloroethylene, 1,2-
Examples thereof include halogenated hydrocarbon solvents such as dichloroethane and chloroform, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and cyclic ether solvents such as tetrahydrofuran and dioxane. These may be used alone or in combination of two or more.

The number average molecular weight (gel permeation chromatography (GPC) method, converted to polystyrene) of the polycarbodiimide resin synthesized using the above components is preferably in the range of 2000 to 15000, particularly preferably 4000. The range is from 10,000 to 10,000.

As the forming material for forming the stretched film of the polycarbodiimide resin of the present invention, other than the polycarbodiimide resin as the main component, other materials may be used as long as the characteristics such as heat resistance of the polycarbodiimide resin are not reduced. Resins may be mixed and a crosslinking agent may be further added.

As the other resin, a polyimide resin,
Examples thereof include epoxy resin, polyether sulfone, polyphenylene sulfide, polyaniline, polyester, polyether ketone, polyarylate, fluororesin, polyamide resin, polyacetal, polystyrene, polyolefin, polyvinyl chloride, and acrylic ester. These can be used alone or in combination of two or more. Then, these resins are mixed by a method such as a solution type or a dispersion type polymer blend.

Examples of the cross-linking agent include conventionally known cross-linking agents such as triallyl cyanurate, pentaerythritol, and acrylate monomers.

Further, during or after the synthesis of the polycarbodiimide resin, if necessary, a filler such as calcium carbonate, an antistatic agent, a plasticizer, a softening agent, an antiaging agent, a stabilizer, a lubricant, a mold release agent. Known additives such as agents and colorants can be appropriately added.

The polycarbodiimide resin film is produced, for example, as follows using the polycarbodiimide resin produced by the above production method.
That is, the polycarbodiimide resin solution is formed into a predetermined film shape, for example, the polycarbodiimide resin solution is formed into a film shape by drying using a known coating method (casting, spin coating, roll coating, etc.). .

The coating and drying temperature of the above polycarbodiimide resin solution must be set to a temperature not lower than Tg and not higher than Tm of the polycarbodiimide resin. By setting such a temperature, a film having excellent flexibility can be obtained. Within the set temperature range, specifically, the coating drying temperature is preferably set to 20 to 150 ° C, more preferably 50 to 120 ° C.
And particularly preferably set to 70 to 100 ° C. That is, if the temperature is lower than 20 ° C., the solvent may remain in the film, and the residual solvent or the like may reduce the reliability of the film, which is not preferable. The coating drying temperature is 1
If the temperature is higher than 50 ° C and is too high, the polycarbodiimide resin is crosslinked and thermosetting proceeds, and in the stretching process of the obtained film, poor stretching of the film occurs or it is difficult to recover the shape before stretching by heat, which is not preferable. .

The polycarbodiimide resin film thus obtained is preferably set to have a thickness of 5 to 100 μm. The thickness is more preferably 10 to 60 μm, and particularly preferably 20 to 50 μm. That is, the thickness is 5μ
If it is less than m, mechanical strength may be poor and stretching may be difficult. On the contrary, if the thickness exceeds 100 μm, voids may occur during coating and drying, and a product of desired quality may not be obtained.

The polycarbodiimide resin stretched film of the present invention is produced, for example, as follows. That is, in consideration of the thickness, Tg, etc. of the film obtained after stretching, the film is heat-stretched in a predetermined one direction (main axis direction) by a conventional method under a predetermined temperature condition suitable for them. The draw ratio is not particularly limited, but usually,
It is 1.5 to 6 times, preferably 2 to 4 times. That is,
If the draw ratio is less than 1.5 times, the properties of the stretched film may not be effectively utilized, and if the draw ratio exceeds 6 times, it may be difficult to achieve stretching depending on the film strength. Is. Furthermore, if desired, it can be stretched in a direction orthogonal to the stretching direction (principal axis direction). The stretch ratio is not particularly limited, but is usually 1.5 to 5 times, preferably 2 to 3 times. When stretching in the main axis direction and the direction orthogonal thereto, the stretching may be performed in any direction first, or the simultaneous biaxial stretching method may be adopted. Then, the film obtained by stretching in the two directions of the main axis direction and the direction orthogonal thereto has improved impact resistance and resistance to tearing.

After the above heating and stretching, cooling is performed while maintaining the tension state (while keeping the dimension in the stretching direction unchanged).

The stretching method is not particularly limited, and a usual method is adopted. For example, a roll drawing method, a long gap drawing method, a tenter drawing method, a tubular drawing method and the like can be mentioned.

By carrying out the stretching as described above, the obtained polycarbodiimide resin stretched film is provided with the property of heat recovery.

The thickness of the polycarbodiimide resin-stretched film thus stretched is preferably set to 70 μm or less, and the thickness varies depending on the film thickness before stretching and the stretching ratio. A more preferable thickness is in the range of 5 to 50 μm. That is, the thickness is 5
If the thickness is less than μm, the mechanical strength will be poor. On the contrary, if the thickness exceeds 70 μm, it will be difficult to produce the film before stretching to a thickness commensurate with the thickness.

The temperature condition during the stretching step is preferably set to 40 to 150 ° C. in order to dry the polycarbodiimide resin so that the curing reaction does not proceed so much. That is, if the temperature is lower than 40 ° C, a sufficient stretch ratio cannot be obtained and the film is easily broken, which is not preferable. Further, when the temperature exceeds 150 ° C., the curing reaction of the polycarbodiimide resin partially proceeds, so that the heat recovery performance tends to decrease.

The stretch ratio (%) of the stretched film made of the polycarbodiimide resin is calculated by the following formula.

[0063]

## EQU1 ## Stretching rate (%) = (L ₁ −L ₀ ) / L ₀ × 100 L ₁ : Length of film after stretching L ₀ : Length of film before stretching

The heat recovery stress from 100% of this polycarbodiimide resin stretched film is usually 100%.
The stress is about kg / cm ^2, which is 10 times or more the stress as compared with the conventional one.

The stretched film of polycarbodiimide resin thus obtained recovers to the shape before stretching by heating at a temperature of Tg or higher, and the recovery rate generally increases as the temperature rises. And the heat recovery of the polycarbodiimide resin stretched film in the present invention means a heat recovery rate of about 50 to 100%. In general, the heat recovery rate, by blowing hot air at a predetermined temperature to the polycarbodiimide resin stretched film to shrink freely,
As a result, the length of the film before and after the shrinkage is measured and calculated by the formula shown below.

[0066]

## EQU00002 ## Heat recovery rate (%) = [(length of film after recovery)-(length of film after stretching)] / [(length of film before stretching)-(of film after stretching) Length)] × 10
0

Further, depending on the shape of the polycarbodiimide resin stretched film, wrinkles may occur during heat recovery.

The elastic modulus of the polycarbodiimide resin stretched film of the present invention is, for example, 1 in the case of a two-fold stretched film using tolylene diisocyanate as a raw material.
60 to 370 kg / mm ² , tensile strength is 3 to 10 kg /
mm ² and elongation are 2 to 70%.

Further, the stretched film made of the polycarbodiimide resin of the present invention has the following thermal characteristics (A) and (B).
Need to have. In addition, Tg and Tm shown below
Are values measured by using a differential scanning calorimeter (DSC) under the conditions of a temperature rising rate of 10 ° C./min.

(A) Tg is in the range of 0 to 150 ° C. (B) Tm is in the range of 200 to 230 ° C.

First, in the above Tm (B), since the polycarbodiimide resin in the present invention has the structure represented by the general formula (1), it has a unique value in the range of 200 to 230 ° C. There is.

On the other hand, the above-mentioned Tg (A) tends to increase as the drying temperature of the film rises. It is speculated that this is because crosslinking is caused by heating and drying. And, the polycarbodiimide resin-made stretched film in the present invention,
Tg is 0 to 150 ° C., more preferably 20 to 13
It is in the range of 0 ° C, particularly preferably 30 to 100 ° C. By setting within this Tg range, various applications utilizing heat recoverability are possible. That is, Tg is 0
In the polycarbodiimide resin stretched film below ℃,
Even if it is left at room temperature, it gradually recovers to its original shape before stretching, so that it cannot be used for practical purposes. Further, in the case of a stretched film made of a polycarbodiimide resin having a Tg of higher than 150 ° C., the temperature for recovering the shape becomes too high and the heat curing proceeds, which makes it difficult to use.

The polycarbodiimide resin stretched film of the present invention can be used as a shrink tube for surface coating by utilizing its heat recovery property. Also, for example,
It can also be used as a binding tape. Further, if the material is not heat-shrinked into a desired shape, it is possible to perform rework in which the material is heated again, stretched, and then contracted again into a predetermined shape. Also, by providing an adhesive layer,
It can also be used as an adhesive tape, and at the time of tape peeling, the tape is shrunk by heating to facilitate peeling.

Next, examples will be described together with comparative examples.

The characteristic values of the polycarbodiimide resins in Examples and Comparative Examples are those measured as follows.

Intrinsic viscosity (ηinh) Tetrahydrofuran was used as a solvent and the viscosity was measured at a temperature of 30 ° C. using an Ostwald viscometer.

Tg and Tm The temperature was measured with a differential scanning calorimeter (DSC-200, manufactured by SEIKO) at a temperature rising rate of 10 ° C./min.

Weight average molecular weight Using tetrahydrofuran as a developing solvent, HL manufactured by Tosoh Corporation
It measured by polystyrene standard conversion using C8020.

Evaluation of shape recovery A stretched film made of a polycarbodiimide resin was blown with hot air at 90 ° C. to freely shrink, the length of the film before and after shrinkage was measured, and the heat recovery rate of this film before stretching was calculated by the following formula. It was calculated.

[0080]

## EQU00003 ## Heat recovery rate (%) = [(length of film after recovery)-(length of film after stretching)] / [(length of film before stretching)-(of film after stretching) Length)] × 10
0

Mechanical Properties The sample was cut into a size of 70 mm × 10 mm and measured using Tensilon STM-50BP manufactured by Toyo Baldwin.

[0082]

Example 1 5.0 g of 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as “MDI”) was mixed with 30 mg of a carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) in 50 ml of tetrahydrofuran at 60 ° C. for 15 hours. The reaction was carried out to obtain a polycarbodiimide resin solution. The intrinsic viscosity (ηinh) of this solution is 8.2,
The number average molecular weight (Mn) was 9,600. Further, in the above formula (1), the number of repetitions n is 47, and R and X are as follows. Next, this solution was hand-coated on a separator and dried at 90 ° C. for 30 minutes to prepare a polycarbodiimide resin film.

[0083]

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Further, the obtained polycarbodiimide resin film was blown with hot air at 90 ° C. to be uniaxially stretched by 2 times, and its shape was temporarily fixed at room temperature to obtain a polycarbodiimide resin stretched film. This stretched film has a Tg of 78 ° C., a Tm of 224 ° C. and a thickness of 30 μm.
m, elastic modulus 230 kg / mm ² , tensile strength 14 kg /
The mm ² and the elongation rate were 36%. Furthermore, when the shape recoverability was measured and evaluated, the heat recovery rate was 100%.

[0085]

Example 2 2,4-tolylene diisocyanate / 2,
6-Tolylene diisocyanate mixture (mixing ratio = 90
/ 10, hereinafter abbreviated as "TDI") in 25 ml of tetrahydrofuran together with 43 mg of carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) at 60 ° C. for 15 hours to obtain a polycarbodiimide resin solution. The intrinsic viscosity (ηinh) of this solution was 0.2 and the number average molecular weight (Mn) was 6700. In the above formula (1), the number of repetitions n is 52, and R and X are as follows. Next, this solution was hand-coated on a separator and dried at 90 ° C. for 30 minutes to prepare a polycarbodiimide resin film.

[0086]

[Chemical 15]

Further, the obtained polycarbodiimide resin film was uniaxially stretched by a factor of 2 in the same manner as in Example 1 above, and its shape was temporarily fixed at room temperature to obtain a polycarbodiimide resin stretched film. . This stretched film has a Tg of 53 ° C., a Tm of 207 ° C. and a thickness of 17
μm, elastic modulus 240 kg / mm ² , tensile strength 5.4 k
The value was g / mm ² and the elongation rate was 68%. Furthermore, when the shape recoverability was measured and evaluated, the heat recovery rate was 100%.

[0088]

Example 3 5.0 g of MDI and 0.35 g of TD were dissolved in 28 ml of tetrahydrofuran to prepare a carbodiimidization catalyst (1-
Phenyl-3-methylphosphorene oxide) 32 mg
The mixture was reacted at 60 ° C. for 3 hours, and distilled water in the same amount as the catalyst amount was added and stirred for 1 hour to obtain a polycarbodiimide resin solution. The intrinsic viscosity (ηinh) of this solution was 2.5, and the number average molecular weight (Mn) was 10,000. Further, in the formula (1), the number of repetitions n is 50, and R and X are as follows. Next, this solution was hand-coated on a separator and dried at 90 ° C. for 30 minutes to prepare a polycarbodiimide resin film.

[0089]

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Further, the obtained polycarbodiimide resin film was uniaxially stretched by 2 times in the same manner as in Example 1 above, and its shape was temporarily fixed at room temperature to obtain a polycarbodiimide resin stretched film. . This stretched film has a Tg of 63 ° C., a Tm of 222 ° C. and a thickness of 25.
μm, elastic modulus 230 kg / mm ² , tensile strength 5.6 k
It was g / mm ² and the elongation rate was 6.8%. Furthermore, when the shape recoverability was measured and evaluated, the heat recovery rate was 100%.

[0091]

Example 4 61 g of MDI was added to 300 g of tetrahydrofuran.
60 ° C. with 380 mg of carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) in ml
At room temperature for 6 hours to obtain a polycarbodiimide resin solution. The intrinsic viscosity (ηinh) of this solution was 2.7 and the number average molecular weight (Mn) was 8000. In addition, the above formula (1)
In, the number of repetitions n is 39, and R and X are as follows. Next, hand coat this solution on the separator,
It was dried at 150 ° C. for 30 minutes to prepare a polycarbodiimide resin film.

[0092]

[Chemical 17]

Further, the obtained polycarbodiimide resin film was uniaxially stretched 3 times in the same manner as in Example 1 above, and its shape was temporarily fixed at room temperature to obtain a polycarbodiimide resin stretched film. . This stretched film had a Tg of 98 ° C., a Tm of 219 ° C. and a thickness of 27.
μm, elastic modulus 250 kg / mm ² , tensile strength 7.5 k
It was g / mm ² and the elongation rate was 13%. Furthermore, when the shape recoverability was measured and evaluated, the heat recovery rate was 100%.

[0094]

Example 5 TDI (5 g) and tetrahydrofuran (25 ml)
With 43 mg of carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) at 60 ° C. for 9 hours, 0.3 ml of m-tolyl isocyanate was added, and the mixture was stirred at 60 ° C. for 30 minutes to obtain a polycarbodiimide resin solution. Got The intrinsic viscosity (ηinh) of this solution is 0.1
3, the number average molecular weight (Mn) was 4,700. Also,
In the formula (1), the number of repetitions n is 36, and R and X are as follows. Next, this solution was hand-coated on a separator and gradually dried at room temperature to prepare a polycarbodiimide resin film.

[0095]

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Further, the obtained polycarbodiimide resin film was uniaxially stretched 6 times in the same manner as in Example 1 above, and its shape was temporarily fixed at room temperature to obtain a polycarbodiimide resin stretched film. . This stretched film has a Tg of 12 ° C., a Tm of 207 ° C. and a thickness of 3 μm.
It was m. Further, the film was not strong enough to measure the mechanical strength. Furthermore, when the shape recoverability was measured and evaluated, the heat recovery rate was 100%.

[0097]

Example 6 4.5 g of MDI and 0.5 g of naphthalene diisocyanate were reacted with 20 mg of a carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) in 25 ml of tetrahydrofuran at 60 ° C. for 10 hours to obtain a polycarbodiimide resin solution. It was The intrinsic viscosity (ηinh) of this solution is 5.6 and the number average molecular weight (Mn) is 7
It was 500. Further, in the above formula (1), the number of repetitions n is 46, and R and X are as follows. Next,
This solution was hand-coated on a separator and dried at 150 ° C. for 1 hour to prepare a polycarbodiimide resin film.

[0098]

[Chemical 19]

Further, the obtained polycarbodiimide resin film was uniaxially stretched by a factor of 2 in the same manner as in Example 1 above, and its shape was temporarily fixed at a temperature of 25 ° C. to give a polycarbodiimide resin stretched film. Obtained. This stretched film had a Tg of 150 ° C., a Tm of 230 ° C., a thickness of 60 μm, an elastic modulus of 300 kg / mm ² , a tensile strength of 15 kg / mm ² , and an elongation of 10%. further,
When the shape recoverability was measured and evaluated, the heat recovery rate was 100.
%Met.

[0100]

Example 7 12 g of TDI was added to 40 m of tetrahydrofuran.
A polycarbodiimide resin solution was obtained by reacting with 103 mg of a carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) in 1 at 60 ° C. for 7 hours.
The intrinsic viscosity (ηinh) of this solution was 0.41 and the number average molecular weight (Mn) was 5400. Further, in the above formula (1), the number of repetitions n is 42, and R and X are as follows. Next, hand coat this solution on the separator and
A film made of polycarbodiimide resin was produced by drying at 0 ° C. under reduced pressure for 2 hours.

[0101]

Embedded image

Further, the obtained polycarbodiimide resin film was uniaxially stretched in the same manner as in Example 1 above.
A stretched film made of polycarbodiimide resin was obtained by stretching 5 times and temporarily fixing the form at a temperature of −20 ° C. This stretched film has a Tg of 0 ° C. and a Tm of 200.
° C., a thickness of 10 [mu] m, the modulus of elasticity 120 kg / mm ^2, a tensile strength of 3.5 kg / mm ^2, elongation was 55%.
Furthermore, when the shape recoverability was measured and evaluated, the heat recovery rate was 100%.

[0103]

[Comparative Example 1] 10 g of MDI in 50 m of tetrahydrofuran
2 at 60 ° C. with 60 mg of carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) in 1
The reaction was carried out for a time to obtain a polycarbodiimide resin solution. The intrinsic viscosity (ηinh) of this solution was 0.82, and the number average molecular weight (Mn) was 4100. In the formula (1), the number of repetitions n is 20, and R and X are as follows. Next, hand coat this solution on the separator and
A film made of polycarbodiimide resin was prepared by drying at 30 ° C. for 30 minutes.

[0104]

[Chemical 21]

Further, the obtained polycarbodiimide resin film was tried to be uniaxially stretched by the same method as in Example 1, but since the film was not flexible, it could not be stretched. It also had no glass transition temperature.

[0106]

Comparative Example 2 Carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) 3 in 5 ml of hexamethylene diisocyanate in 50 ml of tetrahydrofuran
The reaction was carried out with 0 mg at 60 ° C. for 6 hours to obtain a polycarbodiimide resin solution. Intrinsic viscosity of this solution (ηinh)
Was 4.1 and the number average molecular weight (Mn) was 11,000. Further, in the above formula (1), the number of repetitions n is 8
9, R and X are as follows. Next, this solution was hand-coated on a separator and gradually dried at room temperature to prepare a polycarbodiimide resin film.

[0107]

[Chemical formula 22]

Further, the obtained polycarbodiimide resin film was uniaxially stretched by a factor of 2 in the same manner as in Example 1 above, and its form was temporarily fixed at a low temperature (-20 ° C). This stretched film has a Tg of −5 ° C. and a Tm of 100.
° C., a thickness of 20 [mu] m, the modulus of elasticity 100 kg / mm ^2, a tensile strength of 11 kg / mm ^2, elongation was 80%. When this stretched film was left at room temperature, it gradually contracted, which was unsuitable for practical use.

[0109]

Comparative Example 3 Carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) 3 in 5 ml of diphenylmethane diisocyanate in 25 ml of tetrahydrofuran
The reaction was carried out with 0 mg at 90 ° C. for 6 hours to obtain a polycarbodiimide resin solution. Intrinsic viscosity of this solution (ηinh)
Was 3.4 and the number average molecular weight (Mn) was 7400.
Further, in the above formula (1), the number of repetitions n is 36,
R and X are as follows. Next, this solution was hand-coated on a separator and dried at 160 ° C. for 10 minutes to prepare a polycarbodiimide resin film.

[0110]

[Chemical formula 23]

Further, the obtained film of polycarbodiimide resin was uniaxially stretched in the same manner as in Example 1 above.
It was stretched 5 times and its shape was temporarily fixed at a low temperature (25 ° C). This stretched film has a Tg of 155 ° C. and a Tm of 22.
7 ° C., thickness 24 μm, elastic modulus 300 kg / mm ² ,
The tensile strength was 14 kg / mm ² and the elongation was 2.5%. Then, when the heat recovery of this stretched film was measured, it was found that the heat recovery rate was 40% because some curing had progressed.

[0112]

INDUSTRIAL APPLICABILITY As described above, in the present invention, the stretched film made of polycarbodiimide resin is prepared by using the organic solvent solution containing the polycarbodiimide resin represented by the general formula (1), and heating the polycarbodiimide resin. Characteristic T
A polycarbodiimide resin-stretched film is produced by coating and drying under temperature conditions of g or more and Tm or less and stretching in a uniaxial direction. The polycarbodiimide resin stretched film has thermal characteristics of Tg of 0 to 150 ° C and Tm of 200 to 230 ° C. This stretched film made of polycarbodiimide resin is heated to
It has the property of recovering heat to the state before drawing, and by utilizing this property, it can be applied to various fields such as tube material for surface coating, binding tape material, and forming material for binding. .

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masako Maeda 1-2-1, Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (3)

[Claims] 1. A polycarbodiimide resin film uniaxially stretched using a forming material containing a polycarbodiimide resin represented by the following general formula (1) as a main component, and the polycarbodiimide resin film is: A stretched film made of a polycarbodiimide resin, which has the thermal characteristics (A) and (B). (A) The glass transition temperature is in the range of 0 to 150 ° C. (B) The melting point is in the range of 200 to 230 ° C. Embedded image 2. A step of preparing an organic solvent solution containing a polycarbodiimide resin represented by the following general formula (1), and the organic solvent solution being subjected to temperature conditions satisfying the following (a) and (b): A method for producing a stretched film made of a polycarbodiimide resin, which comprises a step of forming a film by coating and drying below, and a step of uniaxially stretching the film. (A) Glass transition temperature or higher of the polycarbodiimide resin contained in the organic solvent solution. (B) Below the melting point of the polycarbodiimide resin contained in the organic solvent solution. Embedded image 3. The glass transition temperature of the polycarbodiimide resin (a) is in the range of 0 to 150 ° C., and (b)
The melting point of the polycarbodiimide resin is 200 to 23
The method for producing a stretched film of a polycarbodiimide resin according to claim 2, wherein the temperature is in the range of 0 ° C.