CN116217911A - Wear-resistant polycarbonate - Google Patents

Abstract

The invention provides a polycarbonate, which adopts amide-containing aromatic phenols with the following formula I as a blocking agent:

Description

A wear-resistant polycarbonate

technical field

The invention relates to a polycarbonate with abrasion resistance, in particular to a polycarbonate with an amide-substituted aryl terminal structure.

Background technique

Polycarbonate plastic has the advantages of low density, good toughness, easy processing and low price, so it is widely used in high-speed rail windows, aviation transparent parts, optical instruments, automotive light bars, construction and other fields. However, due to structural problems, polycarbonate transparent plastics also have their own shortcomings, such as: low surface hardness, poor resistance to ultraviolet radiation, poor scratch resistance, poor solvent resistance, etc. During use, the outer surface is often subject to friction, atmospheric pressure, etc. Dust or surface cleaning and other reasons cause scratches and scratches on the surface of polycarbonate, which affects transparency and appearance, thereby affecting its service life and limiting its application. Therefore, solving the problem of poor friction resistance of polycarbonate surface has become a research hotspot.

At present, the most effective way to solve this problem is to blend and modify polycarbonate, or to coat its surface with a protective coating. The main protective coatings include organic coatings, organic-inorganic hybrid coatings, and inorganic coatings. wait.

Chinese patent CN103319870A reports a polycarbonate wear-resistant modified plastic, adding 10wt% to 20wt% polytetraamide ethylene and a certain amount of polyurethane thermoplastic elastomer to polycarbonate, and finally prepared a low friction coefficient, Small water absorption, stable size, good self-lubricating polycarbonate wear-resistant modified plastic. There is also the patent CN109370425A reporting that the polycarbonate surface is coated with a wear-resistant coating, mainly using ethyl orthosilicate, phenyltrimethoxysilane and γ-(2,3-glycidyloxy)propyltrimethoxysilane, etc. The coating is prepared on the surface of the substrate, and the film formed by the coating liquid on the surface of the substrate has good adhesion, a hardness of 4H, excellent wear resistance, and can pass the water boiling test.

Based on the inhomogeneity of the blending modification and the fact that the coating falls off the substrate, the two methods for improving the wear resistance of polycarbonate materials have certain disadvantages.

Contents of the invention

The invention provides a polycarbonate with a novel end group, which is a polycarbonate prepared by using an amide-substituted aromatic phenol as an end-capping agent. The outstanding advantage of the invention is that the material preparation process is simple, and the wear resistance of the product is better than that of conventional polycarbonate.

The present invention provides a kind of polycarbonate, adopts amide-containing aromatic phenols having following formula I as end-capping agent:

Among them: the hydroxyl group can be in the meta-position or para-position of the amide structure connected to _R1 ; _R1 can be C1-C4 alkyl, or aromatic phenyl, p-tolyl, naphthyl, or heteroatom-containing Chloromethyl, trifluoromethyl, preferably phenyl;

The preferred structure of the amide-containing aromatic phenols is as follows:

Described polycarbonate comprises homopolycarbonate and copolycarbonate, generally comprises the structural unit of following formula II:

Wherein the M ₁ groups are derived from dihydroxy compounds, at least 80% of the total number of M ₁ groups are aromatic structures, and the rest may be aliphatic or alicyclic structures. Preferably, _M is an aromatic organic group, more preferably having the structure of the following formula III:

Where M ₂ and M ₃ are monocyclic aryl groups, Y is a bridging group that separates M ₂ and M ₃ ; the covalent bond in the above formula is usually in the meta or para position between Y and M ₂ and M ₃ ; M ₂ and M ₃ may be unsubstituted phenylene or derivatives thereof, preferably unsubstituted phenylene. Both _M2 and _M3 are preferably p-phenylene, although both may be ortho- or meta-phenylene, or one is ortho- or meta-phenylene and the other is para-phenylene;

The bridging structure Y is a group that separates _M2 and _M3 , the most common being alkyl, especially aliphatic saturated C1-C8 or alicyclic such as methylene, ethylene, isopropylidene, Cyclohexylene, cyclododecylene or 2,2-adamantylene, preferably isopropylidene;

The structure of formula III is derived from an aromatic dihydroxy compound (called bisphenol), and for the sake of simplicity, the aromatic dihydroxy compound is called bisphenol hereinafter. Due to effectiveness and being particularly suitable for the present invention, the bisphenol is preferably bisphenol A, wherein Y is isopropylidene, and _M2 and _M3 are both p-phenylene;

The above-mentioned _M1 group can also be an aliphatic or alicyclic structure, such as 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, cyclohexanedimethanol, iso sorbitol.

The polycarbonate of the present invention can be prepared by interfacial reaction of phosgene and dihydroxy compounds, wherein amide-substituted aromatic phenols are used as chain-blocking agents. The conditions of this type of reaction are well known in the art, and the main process is to use water and water-incompatible solvents such as dichloromethane as a reaction medium, and tertiary amines or quaternary ammonium salts are catalysts (such as triethylamine or tetra-n-butylene). ammonium chloride), and also sodium hydroxide to provide an alkaline environment. The proportion of the chain-terminating agent is usually 1 to 10 mol%, preferably 1 to 5 mol%, of the proportion of the dihydroxy compound. The polycarbonate of the present invention can also be prepared by other methods, and the di-tert-alkylphenol can be changed into carbonate, and the polycarbonate can be prepared through transesterification with a dihydroxy compound.

In a specific embodiment, the polycarbonate is prepared by the following process:

Add 1 mass part of deionized water, 0.05-0.10 mass part of sodium hydroxide, 0.15-0.25 mass part of bisphenol (preferably bisphenol A) and end-capping agent (amide-substituted aromatic phenols) into the glass kettle , purging the glass kettle with nitrogen, and turning on the mechanical stirring to mix evenly to obtain the aqueous phase material liquid;

0.0001-0.0010 parts by mass of catalyst and 1.1-1.5 parts by mass of solvent are used to prepare mixed solution B; wherein, the aqueous phase feed liquid and mixed solution B can also be directly prepared in the same container;

Into the reaction tank at a certain speed, feed the above prepared aqueous phase material solution, mixed solution B and a total of 0.11 to 0.15 parts by mass of phosgene, and continue to drop concentrated lye during the whole process, so that the pH of the system is controlled at 11~ 13, the temperature of the reaction solution was maintained at 20°C to 30°C. Phosgene and bisphenol A continue to react in the reaction tank until the reaction is complete; the concentrated lye is, for example, a 32% sodium hydroxide solution in mass fraction;

The reaction solution is sequentially washed with dilute hydrochloric acid such as 0.4M hydrochloric acid, washed with deionized water three times, and finally settled in methanol to obtain a powder. The powder is vacuum-dried for 10 h at, for example, 130° C. to obtain a dry powder.

The beneficial effect of the invention is that the polycarbonate with excellent abrasion resistance is prepared by selecting amide-substituted aromatic phenols as the end-capping agent for controlling the molecular weight of the polymer. This kind of material can be used in various fields of complex particle abrasion or frequent friction, such as automobile headlights and optical data recording media.

Detailed ways

The present invention is illustrated by the following examples, but the scope of the present invention is not limited to these examples.

The molecular weight of polycarbonate was obtained by Agilent Technologies 1260infinity test, dichloromethane was used as the mobile phase, the flow rate was 1mL/min, and the column temperature and box temperature were both 30°C.

The injection molding machine used for tablet production is a Haitian injection molding machine modeled as MA900II1260.

The abrasion resistance of polycarbonate is to wipe evenly on the surface of polycarbonate sheet with steel wool, use the pressure of 400g weight, the swing speed of 50rpm/min, wipe for a total of 10min, and use the CSI-101 steel wool abrasion tester Test, and then use BYK HAZE-GARD PLUS to test the haze.

Example 1

Add 7L of dichloromethane, 8L of deionized water, 1824g of bisphenol A, 400g of sodium hydroxide, 68.3g of N-(4-hydroxyphenyl)benzamide and 8mL of triethylamine into a 30L glass kettle, purging with nitrogen glass kettle, and turn on the mechanical stirring.

After stirring and mixing evenly, 928 g of phosgene was introduced at a rate of 15 g/min, and 32% concentrated lye was continuously added dropwise during the whole process, so that the pH of the aqueous phase was controlled between 11 and 12. Stir continuously until the acid chloride in the solution reacts completely.

The oil phase was separated from the reaction liquid, and washed with 0.4M dilute hydrochloric acid and deionized water successively. Afterwards, the polycarbonate was separated by precipitation with methanol, and vacuum-dried at 130° C., and then pulverized with a pulverizer to obtain powder.

Take a certain amount of powder for injection molding to prepare a transparent sheet with a thickness of 3 mm. After wiping with a CSI-101 steel wool abrasion testing machine, perform an abrasion resistance test. The results are shown in Table 1 below.

Example 2-3

In Example 1, N-(4-hydroxyphenyl)benzamide was replaced by equimolar 2,2,2-trifluoro-N-(4-hydroxyphenyl)acetamide and 4-chloromethyl- 4'-Hydroxybenzamide, other conditions are the same, experiment, and test under the same conditions, the results are shown in Table 1.

Comparative example 1

8.5 L of dichloromethane, 8 L of deionized water, 1824 g of bisphenol A, 800 g of sodium hydroxide, 48.1 g of p-tert-butylphenol and 10 mL of triethylamine were added to a 30 L glass kettle. The glass kettle was purged with nitrogen, and the mechanical stirring was started. After stirring and mixing evenly, 928 g of phosgene was introduced at a rate of 15 g/min, and 32% concentrated lye was continuously added dropwise during the whole process, so that the pH of the aqueous phase was controlled between 11 and 12. Stir continuously until the acid chloride in the solution reacts completely. The oil phase was separated from the reaction liquid, and washed with 0.4M dilute hydrochloric acid and deionized water successively. Afterwards, the polycarbonate was separated by precipitation with methanol, and vacuum-dried at 130° C., and then pulverized with a pulverizer to obtain powder.

A certain amount of powder was used for injection molding to prepare a transparent sheet with a thickness of 3 mm. After the CSI-101 steel wool was evenly wiped on the surface of the polycarbonate sheet, the abrasion resistance test was carried out. The results are shown in Table 1 below.

Table 1. Polycarbonate parameters

Example Capping agent molecular weight Haze before wiping Haze after wiping 1 N-(4-Hydroxyphenyl)benzamide 26235 0.1% 2.1% Comparative example 1 p-tert-butylphenol 26750 0.1% 10.3% 2 2,2,2-Trifluoro-N-(4-hydroxyphenyl)acetamide 28437 0.3% 1.2% 3 4-Chloromethyl-4'-hydroxybenzamide 27001 0.4% 2.8%

Claims (6)

1. A polycarbonate with abrasion resistance is characterized in that, contains amido-containing aromatic phenols derived from following formula I in its structure:

Wherein: the hydroxyl group is at the meta or para position of the amide structure connected to _R1 ; R ₁ is selected from C1-C4 alkyl, phenyl, p-tolyl, naphthyl, chloromethyl, trifluoromethyl. 2. polycarbonate according to claim 1, is characterized in that, comprises the structural unit of following formula II:

Wherein the M ₁ groups are derived from dihydroxy compounds, and at least 80 mol% of the total number of M ₁ groups are aromatic structures. 3. polycarbonate according to claim 2, is characterized in that, the _{M of} aromatic structure has the structure of following formula III:

Where M ₂ and M ₃ are monocyclic aryl groups, preferably unsubstituted phenylene or its derivatives; Y is an alkyl group, especially aliphatic saturated C1-C8 or alicyclic such as methylene, ethylene group, isopropylidene, cyclohexylene, cyclododecylene or 2,2-adamantylene. 4. The polycarbonate according to any one of claims 1-3, characterized in that it is prepared by reacting phosgene with a dihydroxy compound, wherein the amide-containing aromatic phenols of formula I are used as chain-blocking agents. 5. The polycarbonate according to any one of claims 1-4, characterized in that, when preparing the polycarbonate, the consumption of the amide-containing aromatic phenols of formula I is 1～10mol% of the dihydroxy compound , preferably 1 to 5 mol%. 6. The polycarbonate according to any one of claims 1-5 is used in the field of various complex particle abrasion or frequent friction, such as automobile headlights and optical data recording media.