KR20200042825A - Polycarbonate based protector having oil resistance against compressor refrigerator oil and flame retardant property - Google Patents

Abstract

The present invention relates to a polycarbonate-based protective cover having oil resistance and flame retardancy with respect to a refrigerant oil. The polycarbonate-based protective cover contains polycarbonate, and after being impregnated into the refrigerant oil for more than 48 hours at 70°C, cracks are not generated on the surface.

Description

Polycarbonate-based protective cover with oil resistance and flame retardancy for compressor refrigeration oil {POLYCARBONATE BASED PROTECTOR HAVING OIL RESISTANCE AGAINST COMPRESSOR REFRIGERATOR OIL AND FLAME RETARDANT PROPERTY}

The present invention relates to a polycarbonate-based protective cover having oil resistance and flame retardancy for compressor refrigeration oil.

The compressor is provided in a refrigerator or an air conditioner, and is one of components for constructing a refrigeration cycle, and serves to compress the working fluid that has passed through the evaporator and supply it to the condenser. It is compressed.

The PTC Starter utilizes the property of a Positive Temperature Coefficient Thermistor, which increases in resistance rapidly when the temperature rises and can be mounted on a compressor. Specifically, the PTC starter is a starter device that automatically controls the start-up of the compressor by blocking the circuit by rapidly increasing the resistance of the PTC thermistor itself when a voltage is applied to both ends of the PTC thermistor to a certain temperature or higher.

The PTC starter includes a PTC cover that is formed to surround the PTC thermistor and the PTC thermistor to protect the PTC thermistor.

Patent Document 1 relates to a PTC fixing structure of a hermetic compressor, and in order to solve the problem that the PTC thermistor is detached or loosened from the terminal of the compressor, the PTC thermistor is pushed to the terminal side and fixed to the inside of the PTC cover. Begins to form more government.

Republic of Korea Registered Patent No. 10-1247471 (Registration Date: 2013.03.19)

The PTC cover must meet impact resistance, heat resistance, flame retardancy, eco-friendliness, insulation properties, etc., and have chemical resistance to the refrigerant oil of the compressor.

An object of the present invention is to provide a polycarbonate-based protective cover having oil resistance and flame retardancy for the refrigerating machine oil of the compressor.

An object of the present invention is to provide a polycarbonate-based PTC cover having oil resistance and flame retardancy for the refrigerating machine oil of the compressor.

The problems to be solved by the present invention are not limited to those mentioned above, and the problems to be solved by the present invention not mentioned and the advantages of the present invention can be understood by the following description, and the embodiments of the present invention It will be understood more clearly. In addition, it will be readily understood that the problems to be solved by the present invention and the advantages of the present invention can be realized by means and combinations thereof as set forth in the claims.

The polycarbonate-based protective cover according to the present invention includes polycarbonate, and after impregnating the freezer oil for more than 48 hours at 70 ° C., cracks are not generated on the surface.

The freezer oil may include mineral oil, polyester oil, and mixtures thereof.

The polycarbonate-based protective cover may further include a styrene repeating unit, silicon, and a benzene ring.

The polycarbonate-based protective cover may include an alkali metal, an alkaline earth metal, or a combination thereof, and examples of the alkali metal include sodium (Na) or potassium (K), and examples of the alkaline earth metal Magnesium (Mg) or calcium (Ca).

The polycarbonate-based protective cover satisfies the following (i) to (iii).

(i) A blue flame of a flame with a height of 125 mm and a blue flame of 40 mm inside is applied to the edge of a specimen measuring 125 mm × 13.5 mm × 13 mm with a 20 ° tilt for 5 seconds and for 5 seconds. When the removal was repeated 5 times, there was no ignition.

(ii) A specimen having a thickness of 2.1 mm was pretreated for 24 hours at 15 ° C to 35 ° C, 45% to 75% of constant temperature and humidity conditions, and the end of the glow wire heated to 750 ° C for 30 seconds. When applied to the specimen, after removal of the glow wire, no sparking occurs in the specimen.

(iii) A specimen having a thickness of 2.1 mm was pretreated for 24 hours at 15 ° C to 35 ° C, 45% to 75% of constant temperature and humidity conditions, and the end of the glow wire heated to 850 ° C was held for 30 seconds. When applied to the specimen, the flame generated on the specimen disappears within 30 seconds after the glow wire is removed.

 The polycarbonate-based protective cover may be used as a PTC cover protecting the PTC thermistor.

Since the polycarbonate-based protective cover according to the present invention has oil resistance to the refrigerating machine oil of the compressor, it is possible to implement the protection function of the electronic device even when the compressor refrigerating machine oil leaks.

The polycarbonate-based protective cover according to the present invention can be used as a PTC cover, and has oil resistance to refrigeration oil of the compressor, so that the PTC thermistor can be protected even when the compressor refrigeration oil leaks.

Since the polycarbonate-based protective cover according to the present invention is made of a polycarbonate-based resin composition containing polycarbonate having excellent flame retardant properties, a flame retardant for imparting flame retardant properties is not used or its use can be minimized. It can minimize the deterioration of the physical properties of the resin due to the use of.

Moreover, the polycarbonate-based protective cover according to the present invention does not use a halogen-based flame retardant or can minimize its use, thereby exhibiting eco-friendly characteristics.

In addition to the above-described effects, the concrete effects of the present invention will be described together while describing the specific matters for carrying out the invention.

1 is a schematic exploded perspective view of a compressor equipped with a PC thermistor.
2 is a schematic perspective view of an exemplary polycarbonate-based protective cover of the present invention.
3 to 6 are images of the results of the chemical resistance test.
7 and 8 are SEM-EMS analysis results of an exemplary polycarbonate-based protective cover of the present invention.

The invention is not limited to the contents disclosed below, but can be implemented in various forms, and the contents disclosed below allow the disclosure of the invention to be complete, and the scope of the invention to those skilled in the art to which the invention pertains. It is provided to fully inform, and the invention is only defined by the scope of the claims.

If it is determined that the detailed description of the related known technology may obscure the gist of the technology, the detailed description may be omitted.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from other components, and it is needless to say that the first component may be the second component, unless otherwise stated.

Throughout the specification, unless otherwise specified, each component may be singular or plural. Throughout the specification, when a part is referred to as "including" or "having" a component, it does not exclude other components unless specifically stated to the contrary. It means what can be included.

1 is a schematic exploded perspective view of a compressor 1000 equipped with a PTC thermistor 500. 2 is a schematic perspective view of an exemplary polycarbonate-based protective cover 600 of the present invention.

Referring to FIGS. 1 and 2, the compressor 1000 is generally formed in a substantially cylindrical shape, and an outer shape is formed by the case 200. The case 200 includes an upper case 220 and a lower case 240, and the upper case 220 and the lower case 240 are coupled to each other. Inside the case 200, an exercise device (not shown) operated by a power applied from the outside and a compression mechanism (not shown) generating compression force by the operation of the exercise device (not shown) are accommodated.

The terminal 300 is mounted on one side of the outer surface of the lower case 240. The terminal 300 is to allow external power to be applied to an exercise device (not shown) inside the case 200, and may be mounted to penetrate the outer surface of the lower case 240.

The terminal 300 may be formed in a circular block shape having a predetermined thickness, and a plurality of pins 320 may be protruded on a surface exposed to the outside of the lower case 240. One end of the pin 320 is connected to an exercise device (not shown) provided inside the compressor 1000, and the protruding part of the pin 320 protruding outward of the case 200 is coupled with the PTC thermistor 500 do.

A mounting bracket 400 may be provided on one side of the lower case 240 provided in the terminal 300. The mounting bracket 400 is joined to the outer surface of the lower case 240 by spot welding or the like, and may be combined with the polycarbonate-based protective cover 600.

Mounting bracket 400 may be composed of a first mounting portion 440 and a second mounting portion 460 that are vertically bent at the top and bottom of the captive attachment portion 420 and the captive attachment portion 420 that are in contact with the lower case 240. have. An insertion hole 442 into which the fastening protrusion 630 of the polycarbonate-based protective cover 600 is inserted is formed in the first mounting portion 440, and the second mounting portion 460 is a locking block of the polycarbonate-based protective cover 600. A fastener 462 that engages with the group 620 may be perforated. The terminal 300 is mounted on the captive attachment portion 420 formed between the first attachment portion 440 and the second attachment portion 460.

A polycarbonate-based protective cover 600 is mounted outside the lower case 240. The polycarbonate-based protective cover 600 is a PTC cover by shielding and protecting the PTC thermistor 500 from the outside of the lower case 240. The polycarbonate-based protective cover 600 is a container-type structure in which one side facing the one side of the lower case 240 is opened, so that the polycarbonate-based protective cover 600 is joined to the outer surface of the lower case 240. When mounted, a space for accommodating the PTC thermistor 500 is formed inside the polycarbonate protective cover 600.

A fastening protrusion 630 coupled to the first mounting portion 440 is formed inside the upper end of the polycarbonate-based protective cover 600, and a second mounting portion 460 is provided outside the lower end of the polycarbonate-based protective cover 600. ) And the engaging projection 620 is formed. Between the locking protrusions 620 at the bottom of the polycarbonate-based protective cover 600, a through hole 610 through which a cord connected to the PTC thermistor 500 can enter and exit is formed.

The polycarbonate-based protective cover 600 includes polycarbonate, which imparts flame retardant properties, as a main component, and silicone oil, which provides resistance to refrigeration oil as a sub-component.

The oxygen concentration in the atmosphere is about 20%, and if the oxygen index indicating the amount of oxygen required for combustion is greater than this, flame retardancy is excellent. Since polycarbonate has an oxygen index of approximately 25 to 29, and a melting index of approximately 8 to 12, it easily forms a char during combustion, effectively blocking the movement of gas, and thus It can exhibit high flame retardant properties.

Examples of the polycarbonate include a compound containing a repeating unit represented by the following formula 1, and a compound containing a repeating unit represented by the following formula 1 can be obtained from the synthetic scheme of the following scheme 1.

<Equation 1>

<Scheme 1>

Examples of the silicone oil include compounds represented by the following formula 2, and the polycarbonate-based protective cover 600 may include styrene repeating units and silicone and benzene rings.

<Equation 2>

The silicone oil represented by Formula 2 is a methyl group of the silicone oil represented by Formula 3, which is substituted with a phenyl group, and has a refractive index (25 ° C, 598 nm) of about 1.50 to about 1.52. By the substitution of the phenyl group, the refractive index of the compound represented by Formula 2 is improved, the refractive index may vary according to the content of the phenyl group, and the content of the phenyl group is, for example, the total weight of the silicone oil represented by Formula 2 It may be 30 to 40% by weight based on.

<Equation 3>

The refractive index (25 ° C, 598 nm) of the silicone oil represented by Formula 3 is about 1.40.

The viscosity of the silicone oil represented by Formula 2 may be 1,000 cps to 3,000,000 cps. When the viscosity is less than 1,000 cps, the mechanical properties of the polycarbonate-based protective cover 600 may be lowered, and when the viscosity is more than 3,000,000 cps, the chemical resistance of the polycarbonate-based protective cover 600 may be lowered. In order to prevent or minimize degradation of the mechanical properties and chemical resistance of the polycarbonate-based protective cover 600, the viscosity of the silicone oil represented by Formula 1 may be 10,000 cps to 100,000 cps.

The fact that the polycarbonate-based protective cover 600 includes polycarbonate as a main component means that the content of the polycarbonate is 80% by weight or more and less than 100% by weight based on the total weight of the polycarbonate-based protective cover 600. Based on the total weight of the polycarbonate-based protective cover 600, the content of silicone oil may be 1% to 3% by weight.

The polycarbonate-based protective cover 600 may further include a flame retardant as an auxiliary component to improve flame retardant properties, and the content of the flame retardant is 0.10% by weight to 1.0% by weight based on the total weight of the polycarbonate-based protective cover 600 % Can be.

As the flame retardant, a known flame retardant can be used, and a halogen-based flame retardant and / or a non-halogen-based flame retardant can be used. In terms of harmfulness and environmental compatibility, a non-halogen-based flame retardant can be used as the flame retardant.

Examples of the flame retardant applied to the polycarbonate-based protective cover 600 include at least one of compounds represented by Formula 4 below and / or a phosphorus-based flame retardant.

<Equation 4>

In the above formula 4, M may be an alkali metal or alkaline earth metal, examples of the alkali metal include sodium (Na), or potassium (K), and examples of the alkaline earth metal include magnesium (Mg) or calcium (Ca ). In addition, in Formula 3, X may be at least one of fluorine (F), chlorine (Cl), and bromine (Br) as a halogen element.

The polycarbonate-based protective cover 600 may optionally further include a fluorine resin capable of improving heat resistance and chemical resistance, and examples of the fluorine resin include polytetrafluoroethylene (PTFE). The content of the fluorine resin may be 0 wt% to 0.4 wt% based on the total weight of the polycarbonate-based protective cover 600.

Further, the polycarbonate-based protective cover 600 may optionally further include carbon black. The content of carbon black may be 0% to 1.0% by weight based on the total weight of the polycarbonate protective cover 600.

Hereinafter, the impact resistance, heat resistance, flame retardancy, eco-friendliness, and insulation properties of the polycarbonate-based protective cover 600 will be described in detail based on experimental examples.

Example 1

After preparing a polycarbonate-based composition with the composition shown in Table 1, the obtained polycarbonate-based composition was molded to obtain a polycarbonate-based protective cover.

ingredient CAS No. content(%) Polycarbonate 103598-77-2 97.85 Potassium Perfluoro-butyl Sulfonate 29420-49-3 0.15 Phenyl Methyl Siloxane 1.5 Polytetrafluoroethylene (PTFE) 0 Carbon black 1333-86-4 0.5

Comparative Example 1

A protective cover was obtained using a commercially available flame retardant acrylonitrile-butadiene-styrene (flame retardant ABS) (trade name: AF305). Table 2 below describes the composition of the flame retardant ABS.

ingredient CAS No. content(%) Acrylonitrile-butadiene-styrene (ABS) 9003-56-9 70.0 ~ 90.0 Brominated epoxy resin 40039-93-8 5.0 ~ 20.0 Antimony trioxide (Sb ₂ O ₃ ) 1309-64-4 2.0 ~ 6.0 Impact reinforcement 0.0 ~ 5.0 Antioxidant 0.0 ~ 2.0 slush 0.0 ~ 2.0

Comparative Example 2

A protective cover was obtained using a commercially available flame-retardant polybutylene terephthalate alloy (flame-retardant PBT Alloy) (trade name: LUMAX GP51061FI). Table 3 below describes the composition of the flame-retardant PBT Alloy.

ingredient CAS No. content(%) Acrylonitrile-butadiene-styrene terpolymer 9003-56-9 20.0 ~ 40.0 Brominated epoxy resin 68928-70-1 5.0 ~ 20.0 Glass filament fiber 65997-17-3 5.0 ~ 20.0 Polybutylene terephthalate 24968-12-5 20.0 ~ 40.0 Acrylonitrile-styrene copolymer 1309-64-4 5.0 ~ 20.0 Antimony trioxide (Sb ₂ O ₃ ) 1309-64-4 3.0 ~ 8.0 Other additives Less than 5.0

Comparative Example 3

A protective cover was obtained using a commercially available flame retardant polybutylene terephthalate (flame retardant PBT) (trade name: LUPOX GP2156F). Table 4 below describes the composition of the flame retardant PBT.

ingredient CAS No. content(%) Brominated polycarbonate oligomer 71342-77-3 5.0 ~ 20.0 Glass filament fiber 65997-17-3 5.0 ~ 20.0 Polybutylene terephthalate 24968-12-5 60.0 ~ 80.0 Antimony trioxide (Sb ₂ O ₃ ) 1309-64-4 3.0 ~ 8.0 Other additives Less than 5.0

Comparative Example 4

A protective cover was obtained using a commercially available flame retardant polyphenylene ether (flame retardant mPPO) (trade name: NORYL N300X). Table 5 below describes the composition of the flame retardant mPPO.

ingredient CAS No. content(%) Polyphenylene ether 25134-01-4 41.0 ~ 69.0 High impact polystyrene 9003-55-8 19.5 ~ 33.5 polystyrene 9003-53-6 8.5 ~ 14.5 Triphenyl phosphate (TPP) 115-86-6 1.0 ~ 10.0 Carbon black 1333-86-4 0.0 to 1.0

Comparative Example 5

A protective cover was obtained using a commercially available flame retardant polyphenylene ether (flame retardant mPPO) (trade name: NORYL PX9406). Table 6 below describes the composition of the flame retardant mPPO.

ingredient CAS No. content(%) Polyphenylene ether 25134-01-4 37.4 ~ 57.4 High impact polystyrene 9003-55-8 15.1 ~ 29.1 polystyrene 9003-53-6 6.5 ~ 12.5 Glass 65997-17-3 10.0 ~ 30.0 Triphenyl phosphate (TPP) 115-86-6 0.0 to 1.0 Carbon black 1333-86-4 0.0 to 1.0

Comparative Example 6

A protective cover was obtained using a commercially available flame retardant polycarbonate alloy (flame retardant PC Alloy) (trade name: LOPOX TE5006F). Table 8 below describes the composition of the flame-retardant PC Alloy.

ingredient CAS No. content(%) Brominated epoxy resin 68928-70-1 5.0 ~ 20.0 Polycarbonate 103598-77-2 40.0 ~ 60.0 Polyethylene terephthalate 25038-59-9 40.0 ~ 60.0 Antimony trioxide (Sb ₂ O ₃ ) 1309-64-4 1.0 ~ 6.0 Other additives Less than 5.0

Experimental example

Using Example 1 and Comparative Examples 1 to 6, impact resistance, heat resistance, flame retardancy, eco-friendliness, and insulation properties were tested.

1. Impact resistance

Impact resistance tests were performed on three specimens according to conditions 1) and 2), and the measurement results are summarized in Table 9.

(Condition 1- steel ball drop test)

When a steel ball with a diameter of 51 mm and a diameter of 540 g is dropped at a height of 1291 mm at 25 ° C, cracks should not occur in the specimen.

(Condition 2)

No cracks in the specimen when impacted 3 times with 0.5 ± 0.05J (N / m) using an impact hammer at 25 ℃.

Impact resistance Condition 1 Test result Condition 2 Test result Example 1 Satisfaction Satisfaction Comparative Example 1 dissatisfaction dissatisfaction Comparative Example 2 dissatisfaction dissatisfaction Comparative Example 3 dissatisfaction dissatisfaction Comparative Example 4 Satisfaction Satisfaction Comparative Example 5 Satisfaction Satisfaction Comparative Example 6 Satisfaction Satisfaction

2. Heat resistance

The heat resistance test was performed on the specimens according to conditions 1) and 2), and the measurement results are summarized in Table 9.

(Condition 1)

After leaving the specimen for 2 hours at 150 ℃, there should be no deformation such as dents.

(Condition 2- Ball pressure test)

When a force of 20 N is applied to a specimen with a 5 mm diameter steel ball for 1 hour at 125 ° C, the mark of the thought by the steel ball should be 2 mm or less.

Heat resistance Condition 1 Test result Condition 2 Test result Example 1 Satisfaction Satisfaction Comparative Example 1 Satisfaction Satisfaction Comparative Example 2 Satisfaction Satisfaction Comparative Example 3 Satisfaction Satisfaction Comparative Example 4 Satisfaction Satisfaction Comparative Example 5 Satisfaction Satisfaction Comparative Example 6 Satisfaction Satisfaction

3. Flame retardant

Flame retardance test was performed on the specimens according to conditions 1) to 3), and the measurement results are summarized in Table 9.

Condition 1) A blue flame of a flame with a height of 125 mm and a blue flame of 40 mm inside was applied to the edge of a specimen measuring 125 mm × 13.5 mm × 13 mm with a 20 ° tilt for 5 seconds and for 5 seconds. No ignition when removal was repeated 5 times.

Condition 2) A specimen having a thickness of 2.1 mm was pretreated for 24 hours at 15 ° C to 35 ° C, 45% to 75% of constant temperature and humidity conditions, and the end of the glow wire heated to 750 ° C was held for 30 seconds. When applied to the specimen, after removing the glow wire, no sparking occurs in the specimen.

Condition 3) A specimen having a thickness of 2.1 mm was pretreated for 24 hours at 15 ° C. to 35 ° C., 45% to 75% constant temperature and humidity conditions, and the end of the glow wire heated to 850 ° C. was held for 30 seconds. When applied to the specimen, the flame generated on the specimen disappeared within 30 seconds after the glow wire was removed.

Flame retardant Condition 1 Condition 2 Condition 3 Example 1 Satisfaction Satisfaction Satisfaction Comparative Example 1 Satisfaction dissatisfaction dissatisfaction Comparative Example 2 Satisfaction Satisfaction Satisfaction Comparative Example 3 Satisfaction Satisfaction Satisfaction Comparative Example 4 Satisfaction Satisfaction Satisfaction Comparative Example 5 Satisfaction Satisfaction Satisfaction Comparative Example 6 Satisfaction Satisfaction Satisfaction

4. Chemical resistance (oil resistance)

The chemical resistance test was performed according to the following deposition test conditions, and the measurement results are summarized in Table 12.

Deposition test condition) After the specimen was immersed in the freezer oil for 48 hours or 72 hours at 70 ° C., no cracking occurred on the surface.

The refrigeration oil used for the immersion test is polyester oil or mineral oil, and is shown in Table 13.

Flame retardant 48 hours immersion test results in polyester oil 72 hours immersion test results in polyester oil 48 hours immersion test results in mineral oil 72 hours immersion test results in mineral oil Example 1 Satisfaction Satisfaction Satisfaction Satisfaction Comparative Example 2 dissatisfaction dissatisfaction dissatisfaction dissatisfaction Comparative Example 3 dissatisfaction dissatisfaction dissatisfaction dissatisfaction Comparative Example 4 dissatisfaction dissatisfaction dissatisfaction dissatisfaction Comparative Example 5 dissatisfaction dissatisfaction dissatisfaction dissatisfaction Comparative Example 6 dissatisfaction dissatisfaction dissatisfaction dissatisfaction

Oil type Grade chemical substance Polyester oil Freol Alpha8G Composition of a mixture of 93% NPG and 2-EHA and a mixture of 7% PE and 2-EHA Mineral oil S5HFP

<NPG (Neopentyl Glycol)>

<2-EHA (2-Ethyl Hexanoic Acid)>

<PE (Pentaerythritol)>

3 to 6 is an image of the result of performing a chemical resistance test, specifically, FIG. 3 is an image of a result of performing a immersion test for 48 hours in polyester oil, and FIG. 4 is a immersion test for 72 hours in polyester oil The image of the result is performed, Figure 5 is an image of the result of performing the immersion test for 48 hours in mineral oil, Figure 6 is an image of the result of performing the immersion test for 72 hours in mineral oil. 3 to 6, after performing the deposition test, uniformity and discoloration did not occur on the surface of the polycarbonate-based protective cover of Example 1.

5. Eco-friendly

Whether or not harmful substances (6 heavy metals: Pb, Cd, Cr, Hg, and Br (PBB, PBDE)) were detected in the specimen was measured. As in Table 14, no harmful substances were detected in Examples and Comparative Examples 1 to 6.

Eco-friendly result Example 1 Satisfaction Comparative Example 1 Satisfaction Comparative Example 2 Satisfaction Comparative Example 3 Satisfaction Comparative Example 4 Satisfaction Comparative Example 5 Satisfaction Comparative Example 6 Satisfaction

6. Insulation properties

It was tested whether the specimen satisfies the CTI grade 3 (175V ~ 250V) or more. As a result of the measurement, the specimen satisfies CTI Grade 3 (above 175 V).

Insulation properties result Example 1 Satisfaction Comparative Example 1 Satisfaction Comparative Example 2 Satisfaction Comparative Example 3 Satisfaction Comparative Example 4 Satisfaction Comparative Example 5 Satisfaction Comparative Example 6 Satisfaction

7. Ingredient analysis

SEM-EMS analysis was performed using Example 2. 7 and 8 show the results of SEM-EMS analysis. 7 and 8 are component analysis results of the part indicated by the arrow, respectively, as in FIGS. 7 and 8, carbon (C), oxygen (O), sodium (Na), and potassium (K) in the polycarbonate-based protective cover. ), Chlorine (Cl) was detected.

Example 2

A polycarbonate-based protective cover was obtained in the same manner as in Example 1, except that a mixture of a compound represented by Formula 5 and a compound represented by Formula 6 below was used instead of the perfluoro-butyl sulfonate potassium salt.

<Equation 5>

<Equation 6>

The above-described invention, the above-described embodiments and the accompanying drawings because it is possible for a person having ordinary skill in the art to which the present invention pertains, various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It is not limited by.

Claims (6)

Contains Polycarbonate,
After impregnating the freezer oil for more than 48 hours at 70 ° C, cracks do not occur on the surface.
Polycarbonate protective cover. According to claim 1,
After impregnating the freezer oil for 48 hours to 72 hours at 70 ° C., cracks do not occur on the surface.
Polycarbonate protective cover. According to claim 1,
The freezer oil includes mineral oil, polyester oil, and mixtures thereof.
Polycarbonate protective cover. According to claim 1,
Styrene (styrene) repeating unit, further comprising a silicon (silicon) and a benzene ring (benzene ring)
Polycarbonate protective cover. According to claim 1,
Alkali metal, alkaline earth metal or a combination thereof
Polycarbonate protective cover. According to claim 1,
Polycarbonate-based protective cover satisfying the following (i) to (iii):
(i) A blue flame of a flame with a height of 125 mm and a blue flame of 40 mm inside was applied to the edge of a specimen measuring 125 mm × 13.5 mm × 13 mm with a 20 ° tilt for 5 seconds and for 5 seconds. When removal was repeated 5 times, no ignition occurred;
(ii) The specimen having a thickness of 2.1 mm was pretreated for 24 hours at 15 ° C to 35 ° C, 45% to 75% of constant temperature and humidity conditions, and the end of the glow wire heated to 750 ° C for 30 seconds. When applied to the specimen, after removal of the glow wire, no sparking occurs in the specimen;
(iii) A specimen having a thickness of 2.1 mm was pretreated for 24 hours at 15 ° C to 35 ° C, 45% to 75% of constant temperature and humidity conditions, and the end of the glow wire heated to 850 ° C was held for 30 seconds. When applied to the specimen, the flame generated on the specimen disappears within 30 seconds after the glow wire is removed.

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