TW202138428A - Transparent copolyamide and the preparing method thereof - Google Patents

Abstract

The present invention provides a transparent copolyamide comprising repeat units of formula (A) and formula (B), and the ratio of the repeat units of formula (A) relative to the whole of copolyamide is higher than 50 mol%, wherein A1, R1 and R2 are as defined in the description. The present invention further provides a preparing method of transparent copolyamide as described. With the advantage of higher transparency, the transparent copolyamide can meet the needs of many end products, thereby producing higher economic benefits.

Description

Transparent copolyamide and preparation method thereof

The present invention relates to a polyamide and a preparation method thereof, and particularly relates to a high-transparency copolyamide and a preparation method thereof.

Polyamide material is one of the important engineering plastics. Because of its low density, high mechanical strength, good impact resistance, excellent thermal stability, chemical resistance, abrasion resistance and oil resistance, it is often used in automobiles. , Replace metal parts in the electronics industry to make its products lightweight.

However, the common polyamide materials have high molecular chain arrangement regularity and high crystallinity, causing their appearance to be white and opaque. It is difficult to be used in chemical textiles, aviation, marine exploration, automobile manufacturing, medical departments, electrical industry, etc. Food packaging, window parts of machinery and machinery, and other application fields that require high transparency, have played a role.

At present, the preparation of transparent polyamide materials is to introduce monomers of different structures by copolymerization to increase the disorder and irregularity of the molecular structure, hinder the stacking of molecular chains, reduce the crystallization rate, and make it polymerize. The crystal lattice of the object shrinks into a microcrystalline or amorphous structure, thereby achieving a transparent effect. However, if the introduced monomer contains a linear structure, the degree of damage to the regularity of the molecular arrangement is not much, and the effect of improving transparency is limited; if the introduced monomer contains an aromatic structure, it is due to the rigidity of the benzene ring. It has strong properties and has the disadvantage of insufficient toughness, and there are doubts about yellowing due to conjugation in use. In addition, if a copolymerization method of transesterification is used in the copolymerization process, due to the poor reactivity of the process and the long polymerization time, there are still problems of removal of reaction by-products and solvents, which increases the overall production cost.

In view of this, it is necessary to propose a copolyamide without yellowing phenomenon, low crystallinity, high transparency and a high production efficiency preparation method, which is more suitable for industrialized mass production and meets the current demand for terminal products.

In order to solve the problems of the above-mentioned conventional technology, the present invention provides a transparent copolyamide, which includes repeating units of formula (A) and formula (B), wherein the repeating unit represented by formula (A) is relative to the The molar ratio of the entire transparent copolyamide is above 50 mol% and less than 100 mol%,

In the formula, R ₁ is a C5-C11 straight-chain alkylene; and R ₂ is a straight or branched C2-C10 alkylene.

In a specific embodiment of the present invention, the R ₁ is a linear pentylene group; the R ₂ is a linear or branched octylene group.

In a specific embodiment of the present invention, the molar ratio of the repeating unit represented by the formula (A) relative to the entire transparent copolyamide is 85 to 97 mol%.

In a specific embodiment of the present invention, the haze value of the transparent copolyamide is between 10 and 20%, and the transparency is between 70 and 82%.

In a specific embodiment of the present invention, the transparent copolyamide has a number average molecular weight of 1,000 to 50,000 g/mol and a relative viscosity of 2.7 to 2.9.

The present invention further provides a preparation method of the above-mentioned transparent copolymerized amide, which comprises: in an organic solvent environment, mixing 4,4-diaminocyclohexylmethane and a linear or branched C4-C12 alkylene The aliphatic diacid undergoes a prepolymerization reaction to prepare a prepolymerized salt with a repeating unit of formula (B); and the prepolymerized salt and the C6-C12 endoamide compound are subjected to temperature conditions of 210 to 260°C and 0 to The polymerization reaction is carried out under a pressure of 6 bar to form a transparent copolyamide with repeating units of formula (A) and formula (B).

In a specific embodiment of the present invention, the temperature of the pre-polymerization reaction is between 25 and 70°C.

In another embodiment of the present invention, the molar ratio of the 4,4-diaminocyclohexylmethane to the aliphatic diacid is 1:1 to 1:1.1.

In a specific embodiment of the present invention, the above-mentioned preparation method of the transparent copolyamide further includes firstly dissolving the 4,4-diaminocyclohexylmethane and the aliphatic diamine with the organic solvent before the prepolymerization reaction. acid.

In an embodiment of the present invention, the organic solvent is C1-C4 alcohols, and the alcohols account for 57 to 75% by volume of the total volume of the prepolymerization reaction.

In a specific embodiment of the present invention, the molar ratio of the prepolymerized salt to the C6-C12 endoamide compound is 3-15.

In an embodiment of the present invention, the polymerization reaction is carried out in the presence of deionized water.

In another embodiment of the present invention, the reaction time of the polymerization reaction is 2 to 6 hours.

In an embodiment of the present invention, the polymerization reaction includes performing a first-stage reaction at a first temperature, then heating to a second temperature for a second-stage reaction, and finally at the second temperature, lowering the reaction pressure to proceed. The third stage reaction, and the third stage reaction time is the shortest.

According to the present invention, the repeating unit synthesized from the internal amide compound is the main body of the block copolymerized amide, and the disordered arrangement of the molecules is increased by introducing 4,4-diaminocyclohexylmethane monomer, and is achieved by process control The specific structural ratio of the block copolymer enables the transparent copolyamide of the present invention to have low crystallinity and high transparency, which meets the use requirements of many end products and increases its application value.

The following is a specific embodiment to illustrate the implementation of the present invention. Those skilled in the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied by other different embodiments, and various details in this specification can also be based on different viewpoints and applications, without departing from the spirit of the present invention. In addition, all ranges and values herein are inclusive and combinable. Any value or point falling within the range described herein, for example, any integer can be used as the minimum or maximum value to derive the lower range and so on.

According to the present invention, a transparent copolyamide includes repeating units of formula (A) and formula (B), wherein the molar ratio of the repeating unit represented by the formula (A) to the entire transparent copolyamide is 50 moles. Ear% above and less than 100 mol%,

In the formula, R ₁ is a C5-C11 straight-chain alkylene; and R ₂ is a straight or branched C2-C10 alkylene.

In other embodiments, the R ₁ can be straight-chain pentyl, straight-chain hexyl, straight-chain heptyl, straight-chain octyl, straight-chain nonyl, straight-chain decyl, or straight-chain extension. Undecyl. In addition, R ₂ can be a straight or branched ethylene group, a straight or branched propylene group, a straight or branched butylene group, a straight or branched pentylene group, Linear or branched hexyl, linear or branched heptyl, linear or branched octyl, linear or branched nonyl, or linear or branched Decyl.

The transparent copolyamide of the present invention is a block copolymer, and the copolyamide has the repeating unit represented by formula (A) as the main part. In a specific embodiment, the molar ratio of the repeating unit represented by the formula (A) to the entire transparent copolyamide is 85 to 97 mol%.

In other embodiments, the molar ratio of the repeating unit represented by the formula (A) to the entire transparent copolyamide can be 86, 87, 88, 89, 90, 91, 92, 93, 94, 95 or 96 Mol%.

According to the present invention, the repeating unit represented by the formula (B) provides molecular disorder to destroy the regularity of the overall molecular structure, so that the crystallinity and crystallization rate of the copolymerized amide of the present invention are reduced, so that the obtained The copolyamide material has an amorphous structure, high transparency and excellent toughness.

The present invention uses the structure ratio between the repeating unit of the formula (A) and the repeating unit of the formula (B) in the block copolymer, so that the haze value of the copolymerized amide product is between 10 and 20%, and the transparency is Between 70 and 82%. In other embodiments, the haze value can be 11, 12, 13, 14, 15, 16, 17, 18, or 19%; the transparency can be 71, 72, 73, 74, 75, 76, 77, 78, 79, 80 or 81%.

Regarding the preparation method of the transparent copolyamide of the present invention, the method includes: in an organic solvent environment, the 4,4-diaminocyclohexylmethane and the aliphatic bis The acid is prepolymerized to prepare a prepolymerized salt with a repeating unit of formula (B); and the prepolymerized salt and the C6-C12 endoamide compound are subjected to a temperature condition of 210 to 260°C and a pressure of 0 to 6 bar The polymerization reaction is carried out under the conditions to form a transparent copolyamide with the repeating unit of formula (A) and formula (B).

In other embodiments, the aliphatic diacid may include straight-chain or branched butylene, straight-chain or branched pentylene, straight-chain or branched hexylene, and straight-chain Or branched heptyl, straight or branched octyl, straight or branched nonyl, straight or branched decyl, straight or branched An alkyl group or a linear or branched dodecylene group.

In another embodiment of the present invention, the molar ratio of the 4,4-diaminocyclohexylmethane to the aliphatic diacid is 1:1 to 1:1.1.

In the pre-polymerization reaction procedure of the present invention, the 4,4-diaminocyclohexylmethane used is not limited to its synthesis method, and the common preparation process is prepared by high-temperature condensation of aniline and formaldehyde under acid catalysis. In a specific embodiment, the 4,4-diaminocyclohexylmethane of the present invention preferably uses 4,4-diaminocyclohexylmethane with a purity of more than 99%.

In a specific embodiment of the present invention, the temperature of the pre-polymerization reaction is between 25 and 70°C.

In other embodiments, the temperature of the pre-polymerization reaction may be 30, 35, 40, 45, 50, 55, 60, or 65°C.

In a specific embodiment of the present invention, the above-mentioned preparation method of the transparent copolyamide further includes firstly dissolving the 4,4-diaminocyclohexylmethane and the aliphatic diamine with the organic solvent before the prepolymerization reaction. Acid; wherein the weight ratio of the 4,4-diaminocyclohexylmethane and the organic solvent is 1:1, and the weight ratio of the aliphatic diacid and the organic solvent is 1:5.

In the present invention, the organic solvent is C1-C4 alcohols, such as methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, tert-butanol or a combination thereof, and in a specific implementation In an aspect, the C1-C4 alcohol accounts for 57 to 75% by volume of the total volume of the prepolymerization reaction.

In a specific embodiment, the pre-polymerization reaction is carried out under an inert atmosphere, where the inert gas may be nitrogen.

In a specific embodiment of the present invention, the above-mentioned preparation method of the transparent copolyamide further includes washing the prepolymerized salt with an organic solvent after the prepolymerization reaction and before the polymerization reaction; wherein, the organic solvent is One or more of C1-C4 alcohols, and the same or different organic solvents as the prepolymerization reaction can be used.

In addition, since the pre-polymerized salt in the present invention directly precipitates and precipitates after the pre-polymerization reaction, it can be separated by conventional equipment, such as a solid separation filter device or a centrifugal sedimentation filter device.

Next, in the polymerization procedure of the present invention, the C6-C12 endoamide compound used is not limited to its synthesis method, and the common preparation process is obtained by performing Beckmann rearrangement reaction of the reactant cyclic oxime under acid catalysis. In a specific embodiment, the C6-C12 lactam compound of the present invention preferably uses a C6-C12 lactam compound with a purity of more than 99%.

In a specific embodiment, the molar ratio of the prepolymerized salt to the C6-C12 lactam compound is 3-15.

In another embodiment, the polymerization reaction is carried out in the presence of deionized water.

In another embodiment of the present invention, the reaction time of the polymerization reaction is 2 to 6 hours.

In other embodiments, the reaction time of the polymerization reaction can be 3, 3.5, 4, 4.5, 5, or 5.5 hours; the reaction temperature of the polymerization reaction can be 215, 220, 225, 230, 235, 240, 245, 250 or 255°C; the reaction pressure of the polymerization reaction can be 1, 2, 3, 4 or 5 bar.

In a specific implementation aspect, the polymerization reaction procedure of the preparation method of the present invention is to adjust the polymerization reaction conditions in a three-stage manner to increase the degree of polymerization of the reaction product. In other words, the reaction is performed at the first temperature for a period of time, and then the temperature is increased to the second temperature for a period of time, and finally the reaction pressure is reduced at the second temperature to carry out the third stage reaction, and the third stage reaction takes the shortest time. For example, the first The stage is to react at 220°C for 2 hours; the second stage is to react at 240°C for 2 hours; and the third stage is to reduce the reaction pressure and react at 240°C for 0.5 hours.

In addition, in a specific embodiment, the preparation method of the present invention may further include adding an appropriate amount of antioxidant to the polymerization reaction system to prevent the polymer from chemical reaction or degradation due to heat or shear stress during the preparation process. , Wherein the antioxidant system can be selected from hindered phenols, phosphites or hindered amines.

In another specific embodiment, the preparation method of the present invention may further include adding an appropriate amount of molecular weight regulator to the polymerization reaction system to control the molecular weight of the polymer; wherein, the molecular weight regulator may be a C4-C12 aliphatic Monoacid, C6-C12 aromatic monoacid or dibasic acid; In addition, the molecular weight regulator is particularly preferably glacial acetic acid, benzoic acid or terephthalic acid.

In another embodiment, the weight ratio of the antioxidant and the molecular weight regulator in the polymerization reaction system of the present invention to the overall polymerization reaction system is 0 to 5% by weight.

In other embodiments, the weight ratio of the antioxidant and the molecular weight regulator to the overall polymerization reaction system may be 1, 2, 3, or 4% by weight.

Therefore, the number average molecular weight of the transparent copolyamide prepared by the present invention is 1,000 to 50,000 grams/mole (g/mol), and its relative viscosity is 2.7 to 2.9.

In other embodiments, the number average molecular weight of the transparent copolyamide can be 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 15000, 20000, 25000, 30000, 35000, 40000 or 45000 grams /Mole; the relative viscosity of the transparent copolyamide can be 2.72, 2.74, 2.76, 2.78, 2.80, 2.82, 2.84, 2.86 or 2.88.

In the embodiment of the present invention, the reaction device used in the preparation method of the transparent copolyamide further includes a stirring device, an example of which can be a stirred tank reactor, and the speed of the stirring device is 80 to 150 revolutions per minute. , So that the monomers in the reaction system are uniformly mixed; wherein, the stirring device is Can be selected from propeller stirrer, turbine stirrer, paddle stirrer, anchor stirrer, folding blade stirrer, side-entry stirrer, propeller stirrer, magnetic heating stirrer or ribbon type Stirrer.

After the polymerization reaction of the present invention is completed, the following procedures include: cutting, extracting, and drying the copolyamide product of the present invention in order to improve the purity of the product of the present invention, and the above-mentioned procedures can be processed by conventional equipment. .

The characteristics and effects of the present invention will be further described in detail below through specific embodiments, but the scope of the present invention is not limited by the description of the embodiments.

Example 1:

Take 4,4-diaminocyclohexylmethane and ethanol at a weight ratio of 1; 1 prepare reaction solution A; take sebacic acid and ethanol at a weight ratio of 1; 5 prepare reaction solution B; the completely dissolved reaction solution A, B is added to the reactor so that the molar ratio of 4,4-diaminocyclohexylmethane and sebacic acid in the reactor is 1:1, and the pre-polymerization reaction is carried out under a nitrogen environment and a temperature of 65°C; After the reaction is completed, a white precipitate is deposited, which is filtered, purified by ethanol, and dried to obtain a prepolymerized salt with a repeating unit of formula (B-1).

Then, dissolve the prepolymerized salt (3 mol%) and caprolactam (97 mol%) in deionized water, and place them in a copolymerization reactor with uniform stirring; set the copolymerization reactor at 220°C The polymerization reaction is carried out under temperature conditions and 6 bar pressure conditions for 2 hours; after the reaction is completed, pelletizing, extraction and drying are carried out to obtain a transparent copolymer with repeating units of formula (A-1) and formula (B-1) amine.

The above-mentioned copolyamide products were subjected to the following test analysis and recorded in Table 1:

(1) Relative viscosity test: According to the standard test method of ISO307, the copolyamide product is dissolved in concentrated sulfuric acid to prepare a sample solution with a concentration of 0.54% by weight, and the measurement is carried out at a temperature of 25°C using a capillary viscometer, and according to the standard The formula of RV=t/t ₀ in section 11 of the above calculation is based on the calculation of the relative viscosity.

(2) Melting point value measurement: A differential scanning thermal analyzer (DSC; Perkin Elmer, Diamond DSC) was used to measure the prepared compound at a programmed temperature rise rate of 10°C/min.

(3) Transparency and haze value measurement: The above-mentioned copolymerized polyamide products are hot pressed into a sample film with a thickness of 0.1 cm. According to the standard test method of ASTM D1003, the haze/transparency measuring instrument (KONICA MINOLTA, CM-3600d) is used. ) Measure the transparency and haze value of the sample film.

Example 2:

The preparation method of the copolyamide is the same as in Example 1, except that the molar ratio of the prepolymerized salt in the polymerization reaction is 6 mol%, and the molar ratio of the caprolactam is 94 mol%; The test analysis method in 1 measures the performance of the prepared copolyamide products, and the test results are shown in Table 1.

Example 3:

The preparation method of the copolyamide is the same as in Example 1, except that the molar ratio of the prepolymerized salt in the polymerization reaction is 10 mol%, and the molar ratio of the caprolactam is 90 mol%; The test analysis method of 1 measures the performance of the prepared copolyamide products, and the test results are shown in Table 1.

Example 4:

The preparation method of the copolyamide is the same as in Example 1, except that the molar ratio of the prepolymerized salt in the polymerization reaction is 15 mol%, and the molar ratio of the caprolactam is 85 mol%; The test analysis method of 1 measures the performance of the prepared copolyamide products, and the test results are shown in Table 1.

Comparative example 1:

The preparation method of the copolyamide is the same as in Example 1, except that the molar ratio of the prepolymerized salt in the polymerization reaction is 0 mol%, and the molar ratio of the caprolactam is 100 mol%; The test analysis method in 1 measures the performance of the prepared copolyamide products, and the test results are shown in Table 2.

Comparative example 2:

The preparation method of the copolyamide is the same as in Example 1, except that polyamide (PA66) formed by hexamethylene diamine and adipic acid is used as the prepolymerized salt, and the molar ratio of the prepolymerized salt is 6 mol%, The molar ratio of the caprolactam was 94 mol%; the performance of the prepared copolyamide product was measured by the test analysis method of Example 1, and the test results are shown in Table 2.

Comparative example 3:

The preparation method of the copolyamide is the same as in Example 1, except that polyamide (PA610) formed by hexamethylene diamine and sebacic acid is used as the prepolymerized salt, and the molar ratio of the prepolymerized salt is 6 mol% The molar ratio of the caprolactam was 94 mol%; the performance of the prepared copolyamide product was measured by the test analysis method of Example 1, and the test results are shown in Table 2.

Table 1

Table 2

In summary, in the present invention, the repeating unit synthesized from the internal amide compound is the main body of the block copolymerized amide, and 4,4-diaminocyclohexylmethane monomer is introduced to increase the disordered arrangement of the molecules. The process control realizes the specific structural ratio of the block copolymer, so that the transparent copolyamide of the present invention has low crystallinity and high transparency, which meets the use requirements of many end products and increases its application value.

The above-mentioned embodiments are only illustrative descriptions, and are not used to limit the present invention. Anyone who is familiar with this technique can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention is defined by the scope of the patent application attached to the present invention. As long as it does not affect the effect and implementation purpose of the present invention, it should be covered in the technical content of this disclosure.

Claims (15)

A transparent copolyamide containing repeating units of formula (A) and formula (B), wherein the molar ratio of the repeating unit represented by the formula (A) to the entire transparent copolyamide is more than 50 mol% ,

In the formula, R ₁ is a C5-C11 linear alkylene group; and R ₂ is a linear or branched C2-C10 alkylene group. The transparent copolyamide as described in item 1 of the scope of patent application, wherein the R ₁ is a linear pentylene group. The transparent copolyamide according to the first item of the scope of patent application, wherein the molar ratio of the repeating unit represented by the formula (A) to the entire transparent copolyamide is 85 to 97 mol%. The transparent copolyamide described in item 1 of the scope of patent application has a haze value between 10 and 20%, and a transparency between 70 and 82%. The transparent copolyamide described in item 1 of the scope of patent application has a number average molecular weight of 1,000 to 50,000 g/mol. The transparent copolyamide described in item 1 of the scope of patent application has a relative viscosity of 2.7 to 2.9. A method for preparing the transparent copolyamide as described in item 1 of the scope of patent application, which includes: In an organic solvent environment, prepolymerize 4,4-diaminocyclohexylmethane and aliphatic diacids with linear or branched C4-C12 alkylene to obtain a formula (B) Pre-polymerized salt of the repeating unit; and The prepolymerized salt and the C6-C12 endoamide compound are polymerized at a temperature of 210 to 260°C and a pressure of 0 to 6 bar to form a repeating unit of formula (A) and formula (B) Transparent copolyamide. According to the preparation method described in item 7 of the scope of patent application, the temperature of the pre-polymerization reaction is between 25 and 70°C. The preparation method described in item 7 of the scope of patent application, wherein the molar ratio of the 4,4-diaminocyclohexylmethane to the aliphatic diacid is 1:1 to 1:1.1. The preparation method as described in item 7 of the scope of patent application includes the addition of dissolving the 4,4-diaminocyclohexylmethane and the aliphatic diacid in the organic solvent before the pre-polymerization reaction. According to the preparation method described in item 7 of the scope of the patent application, the organic solvent is a C1-C4 alcohol, and the alcohol accounts for 57 to 75% by volume of the total volume of the prepolymerization reaction. The preparation method according to item 7 of the scope of patent application, wherein the molar ratio of the prepolymerized salt to the C6-C12 endoamide compound is 3-15. The preparation method described in item 7 of the scope of patent application, wherein the polymerization reaction is carried out in the presence of deionized water. The preparation method described in item 7 of the scope of patent application, wherein the reaction time of the polymerization reaction is 2 to 6 hours. The preparation method described in item 7 of the scope of patent application, wherein the polymerization reaction includes performing a first-stage reaction at a first temperature, then heating to a second temperature for a second-stage reaction, and finally at the second temperature, The reaction pressure is reduced to carry out the third stage reaction, and the time of the third stage reaction is the shortest.