KR102034597B1 - Resin composition for automobile glazing - Google Patents

Abstract

The present invention relates to a resin composition comprising a polymethyl methacrylate copolymer that can be used for automobile glazing.

Description

Resin composition for automobile glazing {RESIN COMPOSITION FOR AUTOMOBILE GLAZING}

The present invention relates to a resin composition comprising a polymethyl methacrylate copolymer that can be used for automobile glazing.

In the automotive industry, reducing the body weight is a challenge for reducing CO2 emissions and improving fuel economy.

On the other hand, the demand for the expansion of the glass area, such as the panoramic sunroof on the car body for design, openness, etc. is increasing.

As the glass material applied to the automobile increases the weight of the vehicle body, research is being actively conducted on the technology to achieve light weight as a material that can replace it.

Among these materials, polycarbonate is one of the materials that is drawing attention because it has a specific gravity of about half of glass.

Polycarbonate is a thermoplastic resin having a heat deformation temperature of 135 ° C. or higher, and excellent in transparency, and excellent in impact resistance, dimensional stability, and heat resistance, is widely used in electric and electronic products as well as in the automotive field. In particular, recently, it has been widely used as a glazing material for automobiles using excellent impact resistance and transparency.

However, polycarbonate is poor in scratch resistance and abrasion resistance, low surface hardness is required a high level of hard coating. Hard-coating processes increase costs and cause lower productivity due to additional process steps.

On the other hand, the use of impact-resistant polymethyl methacrylate resin having excellent surface hardness is examined, but this is difficult to apply, such as haze occurs due to the change in refractive index according to the temperature change.

Therefore, it is necessary to research and develop a resin composition for automobile glazing having excellent optical properties such as excellent surface hardness and impact resistance and no haze caused by temperature while being able to replace a glass material to reduce the weight of an automobile.

Korea Patent Registration No. 10-1459130 (2014.10.31)

An object of the present invention is to provide a resin composition for automobile glazing that maintains a high surface hardness and does not generate haze due to temperature change.

Moreover, an object of this invention is to provide the resin composition for automobile glazing excellent in impact resistance and weather resistance.

Moreover, an object of this invention is to provide the resin composition for automobile glazing which is excellent in scratch resistance and abrasion resistance.

In addition, an object of the present invention is to provide a method for producing a polymethyl methacrylate copolymer which is contained in the resin composition for automobile glazing and has a low surface hardness and is excellent in UV stability, impact resistance and light transmittance. .

One aspect of the invention is a core consisting of a copolymer derived from 70 to 100% by weight acrylic acid ester monomer and 0 to 30% by weight methacrylic acid ester monomer and grafted on the core, methacrylic acid ester monomer 50 to 99 The present invention relates to a resin composition for automobile glazing comprising a polymethyl methacrylate copolymer having a core shell structure composed of a shell composed of a copolymer derived from 1% by weight to 50% by weight of an acrylic acid ester.

In the resin composition for automobile glazing according to an embodiment of the present invention, the polymethyl methacrylate copolymer may be composed of 20 to 60% by weight of the core and 40 to 80% by weight of the shell.

In the resin composition for automobile glazing according to an embodiment of the present invention, the polymethyl methacrylate copolymer may have an average particle diameter of 50 to 150nm.

The resin composition for automobile glazing according to an embodiment of the present invention further includes any one or more additives selected from the group consisting of antioxidants, plasticizers, mold release agents, thermal stabilizers, antistatic agents, flame retardants, lubricants, impact modifiers and ultraviolet stabilizers. Can be.

Another aspect of the present invention may be a molded article manufactured from the above resin composition for automobile glazing.

Another aspect of the invention

(A) preparing a core particle for emulsion polymerization by adding a solution in which at least one monomer, an emulsifier, a graft agent, and an initiator selected from acrylic acid ester monomers and methacrylic acid ester monomers is mixed into ion-exchanged water;

(B) a shell layer manufacturing step of coating the particles by emulsion polymerization by adding a methacrylic acid ester monomer, an acrylic acid ester monomer, a chain transfer agent and an initiator to a solution containing particles produced by the emulsion polymerization;

It relates to a method for producing a polymethyl methacrylate copolymer for automobile glazing comprising a.

In the method for producing a polymethyl methacrylate copolymer according to an embodiment of the present invention, the monomer in step (A) may be 70 to 100% by weight of the acrylic ester monomer.

In the method for producing a polymethyl methacrylate copolymer according to an embodiment of the present invention, in the step (B), the methacrylic acid ester monomer is 50 to 99% by weight, the acrylic ester monomer contains 1 to 50% by weight It may be.

In the method for preparing a polymethyl methacrylate copolymer according to an embodiment of the present invention, the step (B) is performed by dividing the monomer into two or more steps, and the content of the acrylic ester monomer is reduced to the next step. And may be to react.

In the method for preparing a polymethyl methacrylate copolymer according to an embodiment of the present invention, the emulsifier may be any one or more anionic emulsifiers selected from alkaline alkyl phosphates and alkyl sulfate salts of 4 to 30 carbon atoms.

In the method for preparing a polymethyl methacrylate copolymer according to an embodiment of the present invention, the graft agent may be any one or more selected from allyl (meth) acrylate and diallyl maleate.

The resin composition for automobile glazing of the present invention maintains a high surface hardness and at the same time does not generate haze due to temperature change, and has excellent optical properties.

In addition, unlike polycarbonate resins have the advantage that hard coating is not required on a high level surface.

In addition, the resin composition for automobile glazing of the present invention has the advantage of excellent impact resistance, weather resistance, scratch resistance and wear resistance.

Hereinafter, with reference to the accompanying drawings will be described in detail a resin composition for automobile glazing of the present invention and a manufacturing method thereof. The invention can be better understood by the following examples. The following examples are for illustrative purposes of the invention and are not intended to limit the scope of protection defined by the appended claims. In this case, unless otherwise defined, the technical and scientific terms used have the meanings that are commonly understood by those of ordinary skill in the art.

In the present invention, the term "(meth) acrylate" refers to acrylate and methacrylate collectively.

The inventors of the present invention recognizes a problem that the polycarbonate resin used as an automobile glazing resin has a low surface hardness and requires a high level of hard coating, thereby increasing costs and adding a process. As a result of further research on the material that can replace the resin, it is possible to provide a polymethyl methacrylate copolymer having a core-shell structure to realize a high surface hardness while minimizing the change in refractive index according to temperature change. It has been found that the present invention can provide a resin composition for automobile glazing that can realize the characteristics, thereby completing the present invention.

One aspect of the present invention is to provide a resin composition for automobile glazing comprising a polymethyl methacrylate copolymer having a multilayer structure of a core-shell. Specifically, the polymethyl methacrylate copolymer is grafted on the core and the core consisting of a copolymer derived from 70 to 100% by weight acrylic acid ester monomer and 0 to 30% by weight methacrylic acid ester monomer , A shell consisting of a copolymer derived from 50 to 99% by weight of methacrylic acid ester monomer and 1 to 50% by weight acrylic acid ester monomer. In this case, in the core made of the copolymer, “copolymer” has a meaning including a case where the methacrylic ester monomer is a homopolymer composed of an acrylic ester monomer when 0 wt%. That is, the core particles may be composed of a homopolymer of an acrylic ester monomer or a copolymer of an acrylic ester monomer and a methacrylic ester monomer. The core particles are 70 to 100% by weight acrylic acid ester monomer and 0 to 30% by weight methacrylic acid ester monomer, preferably 75 to 95% by weight acrylic acid ester monomer and 10 to 25% by weight methacrylic acid ester monomer If the above range is satisfied, it is effective in terms of achieving excellent impact resistance while having optical properties.

The shell layer is formed by grafting to the core particles, 50 to 99% by weight of methacrylic acid ester monomer and 1 to 50% by weight of acrylic acid ester monomer, preferably 55 to 95% by weight methacrylic acid ester monomer And it may include 5 to 45% by weight acrylic acid ester monomer, and when satisfying the above range is effective in improving the impact resistance and weather resistance at the same time while maintaining a high surface hardness and wear resistance, scratch resistance.

The present invention is characterized in that it does not contain an aromatic vinyl compound such as styrene that can be used to have a high refractive index. When the aromatic vinyl monomers such as styrene are used, impact strength and weather resistance are deteriorated, and in particular, haze occurs due to temperature change, and thus optical properties are deteriorated, thereby making it difficult to apply for automobile glazing.

The acrylic ester monomer is an acrylic ester having 1 to 15 carbon atoms, preferably 2 to 8 carbon atoms. Specific examples include ethyl acrylate, n-butyl acrylate, t-butyl acrylate and 2-ethylhexyl acryl. It may be any one or more selected from the group consisting of a rate and octyl acrylate, but is not limited thereto.

The methacrylic acid ester monomer is a methacrylic acid ester of 1 to 15 carbon atoms, preferably 2 to 8 carbon atoms, specifically methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, I- Butyl methacrylate, t-butyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate may be any one or more selected from the group consisting of, but is not limited thereto.

According to one embodiment of the present invention, the polymethyl methacrylate copolymer may be composed of 20 to 60% by weight of the core and 40 to 80% by weight of the shell. Preferably, the core may be 25 to 55% by weight, and the shell may be 45 to 75% by weight, and in the case of satisfying the above range, in view of realizing high surface hardness and impact strength characteristics and excellent light transmittance balance simultaneously effective.

In this case, the core particles may have an average particle diameter of 5 to 50nm, 10 to 40nm. If the above range is satisfied, it is effective in terms of improving impact resistance.

In addition, the polymethyl methacrylate copolymer may have an average particle diameter of 10 to 1,000 nm, specifically 20 to 500 nm, more specifically 50 to 200 nm. If the above range is satisfied, it is more effective in terms of realizing excellent surface properties and mechanical strength, and at the same time excellent optical properties, but this is only one non-limiting example and is not limited to the numerical range.

The resin composition for automobile glazing according to one embodiment of the present invention, if necessary, any one or more additives selected from the group consisting of antioxidants, plasticizers, mold release agents, heat stabilizers, antistatic agents, flame retardants, lubricants, impact modifiers and ultraviolet stabilizers. It may further include, but is not limited thereto.

Another aspect of the present invention is to provide a method for preparing a polymethyl methacrylate copolymer.

Method for producing a polymethyl methacrylate copolymer according to an embodiment of the present invention

(A) preparing a core particle for emulsion polymerization by adding a solution in which at least one monomer, an emulsifier, a graft agent, and an initiator selected from acrylic acid ester monomers and methacrylic acid ester monomers is mixed into ion-exchanged water;

(B) a shell layer manufacturing step of coating the particles by emulsion polymerization by adding a methacrylic acid ester monomer, an acrylic ester monomer, a chain transfer agent and an initiator to a solution containing particles produced by the emulsion polymerization.

Specifically, step (A) is to prepare a rubbery core particle. In the core particle manufacturing step, the ion-exchanged water is added to the reactor under an inert gas atmosphere, and then an emulsifier is added thereto to sufficiently stir. At this time, the ion-exchanged water is preferably 100 to 500 parts by weight, specifically 200 to 400 parts by weight based on 100 parts by weight of the total monomer, the temperature range of the ion-exchanged water may be 50 to 70 ℃. If the above range is satisfied, it is effective to prepare a copolymer having the desired physical properties according to emulsion polymerization.

Thereafter, an emulsion polymerization reaction is carried out with a mixed solution in which any one or more monomers selected from acrylic acid ester monomers and methacrylic acid ester monomers and an emulsifier, a graft agent and an initiator are mixed.

In this case, the acrylic ester monomer is contained 70 to 100% by weight, preferably 75 to 95% by weight relative to the total monomer, when the above range is satisfied is effective in implementing excellent impact resistance without deteriorating other physical properties

The emulsifier is not particularly limited, but preferably any one or more anionic emulsifiers selected from the group consisting of alkaline alkyl phosphates having 4 to 30 carbon atoms, sodium dodecyl sulfate, sodium dodecylbenzene sulfate and alkyl sulfate salts can be used. have. In this case, the emulsifier may be included 0.1 to 5 parts by weight, specifically 0.2 to 4 parts by weight based on 100 parts by weight of the total monomers.

The graft agent may be used any one or more compounds having different reactivity double bond, preferably may be any one or more selected from the group consisting of allyl (meth) acrylate and diallyl maleate, but is not limited thereto. It doesn't happen. The graft agent may be included in an amount of 0.1 to 10 parts by weight, specifically 0.5 to 5 parts by weight, based on 100 parts by weight of the total monomers. When the above range is satisfied, the viscosity can be easily adjusted and polymerization stability can be ensured, and it is effective in terms of implementing mechanical strength such as tensile strength.

The initiator is ferrous sulfate, ethylenediaminetetraacetate sodium, cumenehydro peroxide, diisopropyl benzenehydroperoxide, azobis isobutylonitrile, tertiary butyl hydroperoxide, paramethane hydroperoxide and benzoyl per It may include any one or more selected from the group consisting of an oxide, but is not necessarily limited thereto. In this case, the initiator may be included in 0.001 to 10 parts by weight, specifically 0.05 to 5 parts by weight based on 100 parts by weight of the total monomers.

The core particle manufacturing step may further include a crosslinking agent. The crosslinking agent is 1,2-ethanedioldi (meth) acrylate, 1,3-propanedioldi (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,5-pentanedioldi (meth ) Acrylate, 1,6-hexanediol di (meth) acrylate, divinylbenzene, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, tri Selected from the group consisting of ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polybutylene glycoldi (meth) acrylate and allyl (meth) acrylate It may include any one or more, but is not necessarily limited thereto. The crosslinking agent may be included in an amount of 0 to 10 parts by weight, specifically 0.1 to 5 parts by weight, based on 100 parts by weight of the total monomers, and when the above range is satisfied, the degree of crosslinking may be increased and more effective in improving physical properties. It is only an example, and is not limited to the range of fraud.

The shell layer manufacturing step (B) is a step of forming an outer layer on the surface of the core particle prepared in the step (A).

Specifically, the outer layer is a methacrylic acid ester monomer, acrylic ester monomer, a chain transfer agent and an initiator is put on the reaction solution containing the core particles prepared in step (A) to the emulsion polymerization reaction to coat the inner layer The outer layer is formed.

In this case, in adding the methacrylic acid ester monomer and the acrylic acid ester monomer to the reactor, it is excellent to secure the impact resistance of the polymethyl methacrylate copolymer by dividing at least two or more steps rather than putting the monomer at once. More effective in terms of surface and optical properties. In particular, it is preferable to add while gradually reducing the content of the acrylic ester monomer from the initial step to the next step. That is, to add 50 to 99% by weight of the methacrylic acid ester monomer and 1 to 50% by weight of the acrylic ester monomer relative to the total monomers, it is preferable to divide the process into at least two or more steps, and to add the reactor to the reactor. It is more preferable to divide into steps.

The chain transfer agent may control the molecular weight of the polymethyl methacrylate copolymer, and may use any one or more selected from the group consisting of alkyl mercaptan, benzyl mercaptan and mercaptoic acid having 2 to 18 carbon atoms, and It is not limited to this.

The shell layer manufacturing step may further include a crosslinking agent. The crosslinking agent may be the same as the crosslinking agent previously used for the core particles. The crosslinking agent may be included in an amount of 0 to 10 parts by weight, specifically 0.1 to 5 parts by weight, based on 100 parts by weight of the total monomers.

According to one embodiment of the present invention, after the step (B), when the polymerization reaction of the polymethyl methacrylate copolymer is completed, a coagulation may be performed using a coagulant. Thereafter, the polymethyl methacrylate copolymer may be separated and prepared through a washing and drying process. At this time, the flocculant is preferably an organic acid salt solution, and as a specific example, may be used any one or more selected from the group consisting of sodium acetate, calcium acetate, sodium formate and calcium formate, but is not necessarily limited thereto. The flocculant may be included in an amount of 0.01 to 5 parts by weight, preferably 0.5 to 4 parts by weight, based on the total suspension polymerization solution. Or by spray drying instead of flocculation, washing and drying.

The present invention provides a molded article manufactured using the above resin composition for automobile glazing.

The molded article may replace a part using a glass material of an automobile. The molded article is not particularly limited in the field of application, but may be specifically applied to the automotive and electrical and electronic products fields.

The molded article may have high surface hardness and low haze even with temperature, thereby realizing excellent optical properties, and having excellent impact resistance, abrasion resistance, and scratch resistance.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples. In addition, the content indication in the following examples are parts by weight, and the parts by weight refer to the weight measured based on any one component. That is, based on 250 parts by weight of ion-exchanged water, the content of the remaining components are described as a ratio according to the weight of the ion-exchanged water.

(Example 1)

Preparation of Polymethylmethacrylate Copolymer

(A) step: 250 parts by weight of ion-exchanged water, 0.002 parts by weight of ferrous sulfate, 0.008 parts by weight of EDTA.2Na salt, 0.2 parts by weight of sodium formaldehyde sulfoxylate and 2 parts by weight of sodium dodecyl sulfate in a reactor with a stirrer. It heated up to 65 degreeC after nitrogen substitution. Thereafter, 1/10 of a mixed solution consisting of 27 parts by weight of butyl acrylate, 3 parts by weight of methyl methacrylate, 1 part by weight of allyl methacrylate and 0.05 part by weight of tertiary butyl hydroperoxide was added dropwise thereto for 30 minutes. 9/10 was added dropwise for 90 minutes, followed by stirring for 1 hour, followed by emulsion polymerization. The average diameter of the glassy polymer obtained at this time was 40 nm.

(B) step: Next, 0.5 parts by weight of sodium dodecyl sulfate, 6 parts by weight of butyl acrylate, 24 parts by weight of methyl methacrylate, 0.04 parts by weight of octyl mercaptan, tertiary butyl hydroperoxide After adding 0.05 parts by weight of the mixed solution dropwise over 1 hour, a mixed solution consisting of 4 parts by weight of butyl acrylate, 36 parts by weight of methyl methacrylate, 0.12 parts by weight of dodecyl mercaptan and 0.05 parts by weight of tertiary butyl hydroperoxide was added. The mixture was added dropwise over 1 hour and then polymerized for 1 hour. The average diameter of the final polymer was 60 nm.

Step (C): In order to aggregate the polymethyl methacrylate copolymer, which is the final polymer obtained above, 0.02 parts by weight of calcium acetate is added to 100 parts by weight of solid particles, and the mixture is agglomerated at 70 ° C., and the obtained particle powder is dehydrated in distilled water. After drying at 80 ℃.

The prepared polymethyl methacrylate copolymer was extruded using an extruder to prepare a specimen. Specimens were tested according to the following evaluation items, and the results are shown in Table 1 below.

(Example 2)

In step (B), butyl acrylate and methyl methacrylate were added in two steps as monomers, and the same procedure as in Example 1 was carried out except that they were added all at once.

(Example 3)

In Example 1, it was carried out in the same manner as in Example 1 except that the content of the polymethyl methacrylate copolymer was adjusted to 15% by weight and 85% by weight of the shell.

(Example 4)

In Example 1, it was carried out in the same manner as in Example 1 except that the content of the polymethyl methacrylate copolymer was adjusted to 65% by weight and 35% by weight of the shell.

(Comparative Example 1)

In the step (A), except that 20 parts by weight of butyl acrylate, 8 parts by weight of methyl methacrylate and 2 parts by weight of allyl methacrylate was used in the same manner as in Example 1.

(Comparative Example 2)

In the step (B), except that 40 parts by weight of butyl acrylate and 30 parts by weight of methyl methacrylate was used in the same manner as in Example 1. At this time, the monomer is divided into two steps in Example 1, but first put 16 parts by weight of butyl acrylate and 18 parts by weight of methyl methacrylate, secondly 24 parts by weight of butyl acrylate and 12 parts by weight of methyl methacrylate Put in.

(Comparative Example 3)

In Example 1, it was carried out in the same manner as in Example 1 except that 5 parts by weight of the styrene monomer as a monomer in step (A).

(Comparative Example 4)

In Example 1, it was carried out in the same manner as in Example 1 except that 5 parts by weight of the styrene monomer as a monomer in step (B).

(evaluation)

(1) Transparency and haze: It measured using the hazemeter based on the prescription | regulation of ASTMD1003. At this time, the measurement temperature was measured by dividing into 20 ℃ and 70 ℃.

(2) Izod impact strength: Notched izod impact strength was measured at room temperature according to ASTM D256.

(3) Yellowness Index: Measured according to ASTM D1925.

(4) Pencil hardness: Measured according to the standard of ASTM D3363.

TABLE 1

As shown in Table 1, Examples 1 to 4 according to the present invention had a high transparency in spite of the temperature change, and the haze was very low. In addition, the Izod impact strength is high, but also has a low yellowness, and at the same time exhibits a high surface hardness, showing excellent properties of physical balance. On the other hand, Comparative Examples 1 and 2, unlike the examples, the optical properties were greatly reduced with temperature changes according to the monomer content constituting the core and shell, and the impact strength and the surface hardness properties were low. In addition, Comparative Examples 3 and 4 are prepared by including styrene monomer, and the optical properties are significantly reduced according to the temperature change, and the low surface and impact strengths are also decreased, which is not suitable for use in automobile glazing. It was confirmed.

Although the preferred embodiment of the present invention has been described above, it is clear that the present invention may use various changes, modifications, and equivalents, and that the above embodiments may be appropriately modified in the same manner. Accordingly, the above description does not define the scope of the invention as defined by the limitations of the following claims.

Claims (11)

Core consisting of a copolymer derived from 75 to 95% by weight acrylic acid ester monomer and 5 to 25% by weight methacrylic acid ester monomer and grafted on the core, 50 to 99% by weight methacrylic ester monomer and acrylic acid ester amount Resin composition for automobile glazing comprising a methacrylate copolymer having a core shell structure consisting of a shell consisting of a copolymer derived from 1 to 50% by weight. The method of claim 1,
The methacrylate copolymer is a resin composition for automobile glazing consisting of 20 to 60% by weight of the core and 40 to 80% by weight of the shell. The method of claim 1,
The methacrylate copolymer is a resin composition for automotive glazing having an average particle diameter of 50 to 150nm. The method of claim 1,
The resin composition further comprises at least one additive selected from the group consisting of antioxidants, plasticizers, mold release agents, thermal stabilizers, antistatic agents, flame retardants, lubricants, impact modifiers and ultraviolet stabilizers. A molded article prepared from the composition of any one of claims 1 to 4. (A) Preparation of core particles prepared by emulsion polymerization by adding a solution containing a monomer, an emulsifier, a graft agent, and an initiator containing 75 to 95% by weight of an acrylic acid ester monomer and 5 to 25% by weight of a methacrylic acid ester monomer in ion-exchanged water Steps and
(B) a shell layer manufacturing step of coating the particles by emulsion polymerization by adding a methacrylic acid ester monomer, an acrylic acid ester monomer, a chain transfer agent and an initiator to a solution containing the particles produced by the emulsion polymerization;
Method for producing a methacrylate copolymer for automobile glazing comprising a. delete The method of claim 6,
Methacrylic acid ester monomer in the step (B) is 50 to 99% by weight, acrylic acid ester monomer 1 to 50% by weight of the manufacturing method of the automotive glazing methacrylate copolymer. The method of claim 6,
The step (B) is carried out by dividing two or more steps when the monomer is added, the method of producing a methacrylate copolymer for automobile glazing, characterized in that to reduce the content of the acrylic ester monomer as the next step. The method of claim 6,
The emulsifier is at least one anionic emulsifier selected from alkaline alkyl phosphate and alkyl sulfate salt having 4 to 30 carbon atoms. The method of claim 6,
The graft agent is any one or more selected from allyl (meth) acrylate and diallyl maleate.