KR100604743B1 - Polyamide resin composition - Google Patents

Abstract

The present invention relates to a thermoplastic rubber elastomer, a polyphenylene maleimide copolymer grafted with maleic anhydride, an unsaturated compound containing an oxirane group, a polyamide resin composition containing a styrene compound, and the composition may be coated without a primer. In addition, it is excellent in impact strength, stiffness and moldability, and excellent in heat resistance and water resistance. It is a composition that can significantly reduce the cost of the existing coating method even in the manufacturing cost of the product. It is a composition which has the characteristic which is excellent in a flow mark, a silver bath, etc.

Description

Polyamide resin composition             

1 is a plan view of a mold for producing a specimen for evaluation of formability,

2 is a cross-sectional view taken along the line A-A of FIG.

3 is a cross-sectional view taken along the line B-B in FIG.

The present invention relates to a polyamide resin composition, and more particularly to a polyamide resin composition excellent in not only coating performance but also impact resistance of a product, processability during molding, and the like.

Polyamide resins are well suited for all industries due to their excellent functionality and reasonable cost. In terms of functionality, polyamide resins have advantages such as stiffness, toughness, wear resistance, moldability, secondary processability, chemical resistance, reinforcing agent addition effect, and beautiful surface of the product, but due to amide bond (-CO-NH-) Poor dimensional stability due to moisture absorption, whitening, bubbles, etc. during molding, and crystalline polymers have a disadvantage in that the impact strength is poor. In addition, polyamide is required for application to parts requiring secondary processing such as coating. The resin is restricted in the painting process.

The painting process is generally divided into three processes. The first step is a primer treatment step, which is a pretreatment step to enhance the interfacial adhesion between the resin and the base coating solution (paint), and then the base coating step. This step is to paint the surface. In the case of the surface of the resin that is not subjected to the primer pretreatment, a number of problems occur during coating, such as swelling, cracking, and poor gloss due to a decrease in interfacial adhesion. As the last step of the painting process, the paint applied to the resin surface by the top clear coating process should be protected from the outside and should have a gloss performance, weather resistance performance, etc.

The coating process of polyamide resin is also done through these three processes, but it varies from product to product, but in general, parts that require painting have excessive coating costs, which entails a fairly high cost. Although there is a difference, the coating cost is about 30 ~ 40% of the primer process, 40 ~ 50% of the base coating process, and 25 ~ 30% of the top coating process. Even if omitted, the manufacturing cost can be substantially reduced.

As an example of the development of an industry capable of omitting primers, acrylonitrile butadiene styrene resin, which is one of general-purpose resins, is partially modified to provide a composition which can be obtained by such a primer elimination process, and a polyphenylene oxide and a polystyrene alloy composition ( m-PPO resin) is also known as a resin having a characteristic of exhibiting coating performance without a primer process. Both of these resins are amorphous resins, which are known to exhibit primer-free paintability due to the surface erosion / elution of the coating, that is, the base coating liquid, due to their lower chemical resistance. It is disadvantageous in that impact resistance, heat resistance, and stiffness are lowered compared with resins before coating.In addition, the coating method, which has recently been in the spotlight, is insufficient in heat resistance of 130 ° C or higher during on-line coating. Restricted

Therefore, polyamide resins can be applied for excellent use as a composition having much better heat resistance, impact resistance, and rigidity at the same coating cost as long as it is possible with such a method of painting. Of course, as mentioned above, polyamide resin itself is impact resistant. This shortage requires modifications and modifications for primerless coatings.

Typically, in order to maximize the impact strength of the polyamide resin, the rubber (Rubber) component is added in an excessive amount, but the impact strength may be good, but the bending elastic modulus causes a mutually opposite characteristics. In addition, there is a problem that the surface of the product is not beautiful because the crystallization rate of the polyamide resin is fast in the case of injection molding of a complex and thin structure. The main molding problems are weld lines, flow marks, and silver baths.

When it is applied to wheel cover of vehicle, lid filler part, out door handle, outdoor chair part, etc., the painting process is involved. There is a problem that the quality is deteriorated due to the gloss decrease.

Conventionally, techniques for blending polyolefin-acid copolymers have been proposed in US Pat. Nos. 4,174,358 and 4,593,066 for the purpose of improving the impact resistance and water resistance of polyamide resins. However, the above-described prior art is a technique used to improve the impact resistance and poor water resistance of polyamide resins in terms of its effect, but it has the effect of modifying impact resistance and water resistance, but it is accompanied by a decrease in heat resistance and stiffness, and coating performance without primer is to be expected. I can't.

In addition, Japanese Patent Application Laid-Open No. 3,185,056 and European Patent Nos. 0560447A1 and 0050206A2 propose a method of improving impact resistance, rigidity, and water resistance by alloying with polyphenylene ether resin, but the polyamide resin obtained by such a method. The composition has insufficient impact resistance and difficulty in molding, so its use is restricted and its compatibility with polyamide and polyphenylene ether resin is poor, resulting in an increase in manufacturing cost due to the addition of a large amount of compatibilizer. . In addition, the primer-free coating effect is expected to be locally possible, but is not satisfactory level due to poor physical properties, such as weather resistance.

In the case of Japanese Patent Application Laid-Open No. 6357301, the invention relates to the use of wheel covers for automobiles, and it is introduced as a technical content regarding the coating performance of the base coating and the top cover coating. It is mentioned as a matter and there is a limit to its technical ability to overcome the lack of impact resistance and rigidity.

Therefore, the main object of the present invention is to provide a polyamide resin composition that exhibits excellent coating performance even by base coating without a primer treatment step.

It is still another object of the present invention to provide a polyamide resin composition having excellent impact resistance, workability in molding, and the like.

In the research for achieving the above object, the present inventors found that adding an appropriate amount of four specific modifiers to the polyamide resin and melt kneading can provide a polyamide resin composition meeting the above object. The present invention has been completed based on facts.

-올레핀류, 아크릴산이나 그 유도체, 방향족 비닐계 단량체 및 시안화 비닐 단량체로 이루어진 군에서 선택되는 공중합 가능 화합물과 올레핀계 단량체와의 공중합체에

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체가 그라프팅된 열가소성 고무탄성체 5∼15중량%; (b) 제2개질제로서 페닐렌말레이미드와 방향족 비닐화합물이 공중합된 폴리페닐말레이미드 공중합체에

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체가 그라프팅된 것 5∼20중량%; (c) 제3개질제로서 아크릴계 고무 또는 디엔계 고무로 이루어진 고무성분과 이 고무성분에 그라프트 가능한 불포화화합물로 되는 코어쉘 형태의 공중합체에 옥실란기 함유 불포화 화합물이 공중합된 것 1∼5중량%, (d) 제4개질제로서 무수말레익산이 그라프팅된 스티렌무수말레익산 공중합체 0.2∼0.6중량% 배합된 것을 특징으로 하는 폴리아미드 수지 조성물이 제공된다.Therefore, according to the present invention, in the polyamide resin composition, based on 60.8 to 87.7% by weight of the polyamide resin which is the base resin and the total weight of the composition, (a) Ethylene,

-Copolymers of copolymerizable compounds selected from the group consisting of olefins, acrylic acid or derivatives thereof, aromatic vinyl monomers and vinyl cyanide monomers with olefin monomers

,

Unsaturated carboxylic acids or

,

5 to 15% by weight of a thermoplastic rubber elastomer grafted with an unsaturated anhydride or a derivative thereof; (b) a polyphenylmaleimide copolymer copolymerized with phenylene maleimide and an aromatic vinyl compound as a second modifier;

,

Unsaturated carboxylic acids or

,

5 to 20% by weight of grafted unsaturated anhydrides or derivatives thereof; (c) 1 to 5% by weight of an oxysilane-containing unsaturated compound copolymerized with a rubber component consisting of an acrylic rubber or a diene rubber as a third modifier and a core-shell copolymer comprising an unsaturated compound graftable to the rubber component and (d) 0.2 to 0.6 wt% of styrene maleic anhydride copolymer grafted with maleic anhydride as a fourth modifier.

Hereinafter, the present invention will be described in more detail.

The polyamide composition according to the present invention contains four modifiers.

First, a modifier commonly referred to as an impact resistant agent is used, which must have a functional group capable of excellent reaction with the polyamide resin, as well as a polar group at the time of coating, which must have a synergistic effect on the coating performance. The impact modifiers used are thermoplastic elastomers grafted with unsaturated carboxyl groups and their use in polyamide compositions is well known as a significant technological advance.

The second modifier also needs to have a functional group because of its excellent compatibility with not only polyamide resins but also impact modifiers, and it has to be excellent in coating performance due to its polarity in coating, as well as improving heat resistance, rigidity and impact resistance. There should be a back. In addition, commercially used end product applications have to be excellent in injection molding processability because they are commercialized by injection molding. The compound used is a polyphenylmaleimide copolymer, which means that the melt viscosity rises, that is, the melt index drops, resulting in flowability. Actually, there is no problem in resin flow in a cold mold, but rather structural flow. In the case of resin products flowing through difficult structures, stress is excessively concentrated due to rapid flow shape change, which solves the problem of surface problems during painting due to weld lines, flow marks, and silver. In detail, this compound has a high melt viscosity but a low solidification rate / temperature, and also plays a role in maintaining a constant viscosity or temperature of the resin filled in the mold. In other words, the gate part of the product is smoothly filled in any form at high temperature / high pressure, but at the end, a sharp shear occurs at the mold wall due to a sharp drop in temperature / pressure, resulting in a sharp increase in the share viscosity. The difference between the viscosity and the initial gate area is small so that the filling is smooth and the melt index is low but a good surface product can be obtained. This is also a feature that allows the injection molding at a low speed during the injection molding of the product. Do.

Another modifier is an oxirane group containing unsaturated compound that is added as a paint modifier for even better paint performance in the properties previously used. This compound is less responsive to polyamide resins than unsaturated carboxylic acids such as maleic anhydride, but has an excellent effect to enhance adhesion to paints by imparting polar groups on the surface.

In addition, the composition is added with a styrenic compound grafted with maleic anhydride as another coating performance modifier. This compound not only acts as a compatibilizer between the polyamide resin and the phenylenemaleimide compound, but also exhibits excellent coating performance due to the introduction effect of the polar group.

The present composition will be described in more detail as follows.

As a polyamide resin used as a base resin in this composition, the polyamide 66 resin which has a structure of Formula 1, and the polyamide 6 resin which has a structure of Formula 2 are preferable.

Where n is a repeating unit and an integer from 500 to 15,000.

Where n is a repeating unit and an integer from 500 to 15,000.

In general, polyamide 66 resin is a hexamethylenediamine adipate salt, which is a polyamide polymerization raw material, in a polyamide resin polymerization autoclave equipped with a stirrer, a heat sensor, a thermostat and a steam reflux cooler. AH salt ') and the appropriate amount of water according to the concentration of this AH salt is added and dissolved uniformly using a stirrer while raising the temperature, and then various additives are added. A uniform slurry using a mixed solvent of methanol and water in a container for preparing raw materials. To prepare a polyamide 66 of the desired properties according to the conventional polyamide 66 production process by introducing into a reaction tube in which the AH salt is dissolved. Typical manufacturing process conditions are shown in Table 1. In addition to the above-mentioned raw materials, acetic acid can be added as a viscosity stabilizer and hexamethylenediamine and antifoaming agent can be additionally added as an excess additive, and oxygen is removed while purging high-purity nitrogen gas after all raw materials are put into the reaction tube. The desired polyamide 66 resin can then be obtained.

  step   Pressure (Kg / ㎠)    Temperature (℃)   Time (minutes)  Temperature rise   Atmospheric pressure-> 17.5    120-> 230        60   Suppression   Keep at 17.5    230-> 255        80   Decompression   17.5-> normal pressure    255-> 270        70   maintain     Atmospheric pressure    270-> 275        30   Discharge   Pressure-> 2.5    275-> 280        20

Under the conditions of Table 1, the pressure rises because the steam is charged in the autoclave as the temperature is increased in the step-up and temperature increase stages. At this time, it raises to 230 degreeC over 60 minutes from the temperature which becomes 120 degreeC. And when the pressure is 17.5 Kg / ㎠ to maintain the pressure while flowing steam to the outside and raise the temperature to about 250 ℃. The pressure is lowered to atmospheric pressure for 70 minutes while flowing out to the outside again, maintained for 30 minutes, stabilized, and then introduced with nitrogen at about 2 to 2.5 Kg / cm 2 to obtain a desired polyamide 66 resin through a discharge process.

In the case of polyamide 6 resin, it can also be prepared according to a conventional method, which will be described in more detail with reference to one example of preparation thereof. 0.003 to 0.005 parts by weight of 1 of tris- (2.4-dibutyl butylphenyl) -phosphite and N-N'-hexamethylene bis (3.5-dibutyl butyl-4-hydroxy-hydrocinamide), a heat-resistant agent A polyamide 6 resin can be prepared by reacting 0.08 to 0.1 parts by weight of Iganox B 1171 (available from Ciba Gage), a 1: 1 mixture. Typical conditions for the preparation of polyamide 6 are shown in Table 2.

  step   Pressure (Kg / ㎠)     Temperature (℃)   Time (minutes)  Temperature rise   Atmospheric pressure-> 15   120-> 260        60   Suppression    15 days   260 maintenance        30   Decompression      0   260-> 255        90   Atmospheric pressure      0   255-> 265        30   vacuum   -360 mmHg   265 maintenance        60

In the case of polyamide 66 and polyamide 6, which can be obtained by the above method, it is preferable to make a chip form for the final resin composition according to the present invention and to dry it at 90 ° C. for 5 hours in a dehumidifying dryer.

Although not particularly limited, the polyamide resin used as the base resin of the present composition is preferably one having a relative viscosity (a solution of 1 g of polyamide in 100 ml of 20% 96% sulfuric acid) of 2.4 to 3.4. If the viscosity of the polyamide resin used is less than the above range, it may lead to a decrease in rigidity, impact strength and heat resistance, and in the case of excess viscosity, high viscosity is accompanied by overpressure during molding. May be accompanied by.

As the polyamide resin, which is the base resin of the present composition, a copolymerized polyamide resin can be used in addition to the above-described polyamide 66 and 6, but polyamide 66 and polyamide 6 are more preferable.

The polyamide resin in the composition is preferably 60.8 to 87.7% by weight. If the content of polyamide resin is too small, the rigidity and heat resistance may be lowered, and too high viscosity may be accompanied, and excessive melt viscosity may limit the application of the application.Too much polyamide resin may make primer-free coating performance difficult and mold shrinkage may increase. And there is a disadvantage that the surface of the molded product is poor,

-올레핀류, 아크릴산이나 그 유도체, 방향족 비닐계 단량체 및 시안화 비닐 단량체로 이루어진 군에서 선택되는 공중합 가능 화합물과 올레핀계 단량체와의 공중합체에

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체가 그라프팅된 열가소성 고무탄성체이다. 그라프팅은 용매상 또는 과산화물의 존재하에 용융된 올레핀류 상에서 수행되며 이러한 그라프팅 기술은 공지되어 있다. Thermoplastic rubber elastomers used as the first modifier in the composition are known as impact or water resistant modifiers of conventional polyamide resins. Such thermoplastic rubber elastomer is ethylene,

-Copolymers of copolymerizable compounds selected from the group consisting of olefins, acrylic acid or derivatives thereof, aromatic vinyl monomers and vinyl cyanide monomers with olefin monomers

,

Unsaturated carboxylic acids or

,

-Unsaturated anhydride or its derivatives are grafted thermoplastic rubber elastomers. Grafting is carried out on solvents or on molten olefins in the presence of peroxides and such grafting techniques are known.

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체는 폴리아미드의 매트릭스 관능기, 즉 아마이드기와 반응성이 우수한 관능기이다. Grafted

,

Unsaturated carboxylic acids or

,

-Unsaturated anhydrides or derivatives thereof are functional groups having excellent reactivity with the matrix functional groups of polyamides, that is, amide groups.

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체의 대표적인 것으로 무수말레익산, 무수이타콘산, 무수시트라콘산, 아크릴산, 메타크릴산, 알릴숙신산, 2-디카르본산, 말레인산, 푸말산, 말레인산디에틸, 말레인산디메틸, 말레산 무수물, 이타콘산 무수물, 시트라콘산 무수물, 알릴숙신산 무수물, 4-메틸-4-사이클로헥센-1 등이 있다.

,

Unsaturated carboxylic acids or

,

Typical examples of unsaturated anhydrides and derivatives thereof include maleic anhydride, itaconic anhydride, citraconic anhydride, acrylic acid, methacrylic acid, allyl succinic acid, 2-dicarboxylic acid, maleic acid, fumaric acid, diethyl maleate, dimethyl maleate, and maleic acid. Acid anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, 4-methyl-4-cyclohexene-1 and the like.

-올레핀류로는 프로필렌, 부틸렌, 1-펜텐, 이소부틸렌, 이소프렌, 1-헥센, 1.3-헥사디엔, 1-헵텐과 같은 것와 비닐아세테이트 또는 프로피오네이트와 같은 포화 카르본산의 비닐에스테르 등이 있고, 아크릴산이나 그 유도체로는 메타크릴레이트, 메틸아크릴레이트, 부틸아크릴레이트, 그리시딜아크릴레이트, 에틸메타크릴레이트, 2-에틸헥실메타크릴레이트, 하이드뢸에틸메타크릴레이트, 아미노메타크릴레이트, 그리시딜메타크릴레이트와 말레이미드 화합물로 N-페닐말레이미드, N-메틸말레이미드, N-사이클로헥실말레이미드 등이 있다. 또한 방향족비닐 단량체 및 시안화 비닐 단량체의 공중합체로는 스틸렌,

-메틸스틸렌, o-메틸스틸렌, p-메틸스틸렌, tetra-부틸스틸렌, 디메틸스틸렌, 클로로스틸렌, 디클로로스틸렌, 비닐나프탈렌과 아클릴로니트릴, 메타크릴로니트릴, 푸마로니트릴 등을 들 수 있다, 디엔계 단량체로는 부타디엔, 1.3-사이클로헥사디엔, 1.4-사이클로헥사디엔, 사이클 로펜타디엔, 2.4-헥사디엔등을 들 수 있다.

-Olefins such as propylene, butylene, 1-pentene, isobutylene, isoprene, 1-hexene, 1.3-hexadiene, 1-heptene and vinyl esters of saturated carboxylic acids such as vinyl acetate or propionate Acrylic acid and its derivatives include methacrylate, methyl acrylate, butyl acrylate, glycidyl acrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate and amino methacrylate. As the glycidyl methacrylate and maleimide compound, there are N-phenylmaleimide, N-methylmaleimide, N-cyclohexyl maleimide and the like. In addition, as a copolymer of an aromatic vinyl monomer and a vinyl cyanide monomer, styrene,

-Methyl styrene, o-methyl styrene, p-methyl styrene, tetra-butyl styrene, dimethyl styrene, chloro styrene, dichloro styrene, vinyl naphthalene and acrylonitrile, methacrylonitrile, fumaronitrile, etc. are mentioned, diene Examples of the system monomers include butadiene, 1.3-cyclohexadiene, 1.4-cyclohexadiene, cyclopentadiene, and 2.4-hexadiene.

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체가 그라프팅되는 공중합체의 예로는 에틸렌프로필렌 공중합체, 에틸렌프로필렌디엔 공중합체, 스틸렌에틸렌부타디엔스틸렌 공중합체, 스틸렌부타디엔스틸렌 공중합체, 에티렌에틸아크릴레이트 공중합체 등이 있다.

,

Unsaturated carboxylic acids or

,

Examples of the copolymer to which the unsaturated anhydride or its derivative is grafted include ethylene propylene copolymer, ethylene propylene diene copolymer, styrene ethylene butadiene styrene copolymer, styrene butadiene styrene copolymer, ethylene ethyl acrylate copolymer and the like.

,

-불포화카르본산 화합물중 무수말레익산이 0.4내지 10중량% 그라프팅되어 있는 에틸렌프로필렌 공중합체이다. 무수말레익산 0.4중량% 미만은 폴리아미드와 상용성이 떨어지고 10중량% 초과는 높은 점도 상승을 수반하여 혼련이 어렵기 때문이다.Particularly preferred thermoplastic rubber elastomers for addition to the composition are

,

It is an ethylene propylene copolymer grafted 0.4 to 10 weight% of maleic anhydride in an unsaturated carboxylic acid compound. This is because less than 0.4% by weight of maleic anhydride is incompatible with polyamide and more than 10% by weight is difficult to knead with high viscosity rise.

As for the usage-amount of the thermoplastic rubber elastic body which is a 1st modifier in this composition, 5-15 weight% is suitable. If less than 5% by weight of the impact effect of the impact strength is insignificant and more than 15% by weight may cause problems such as heat resistance, stiffness is lowered and mold shrinkage is increased.

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체가 그라프팅된 것이 사용된다. The composition includes a polyphenylmaleimide copolymer copolymerized with phenylene maleimide and an aromatic vinyl compound as a second modifier.

,

Unsaturated carboxylic acids or

,

Ungrafted anhydrides or derivatives thereof are used.

 What is important in the copolymer in which the phenylenemaleimide component and the aromatic vinyl compound component are copolymerized is that either component is less than 40% by weight or does not exceed 60% by weight. If the phenylmaleimide is less than 40% by weight, it may cause heat resistance deterioration, poor degree of polymerization, and poor impact resistance.If it exceeds 60% by weight, the cost increases, making the kneading difficult due to uneconomical and too high viscosity. Not preferred.

-메틸스티렌, 메틸스틸렌, 비닐크실렌, 모노클로로스틸렌, 디클로로스틸렌, 모노브로모스틸렌, 디브로모스틸렌, p-t-부틸스틸렌, 에틸스틸렌 비닐나프탈렌, o-메틸스틸렌중에서 선택하여 단독으로 사용하거나 2종 이상을 병행하여 사용할 수 있으며 바람직하게는 스티렌을 단독으로 사용하는 것이다. Examples of the aromatic vinyl compound to be copolymerized include styrene,

-Selected from methyl styrene, methyl styrene, vinyl xylene, monochloro styrene, dichloro styrene, monobromo styrene, dibromo styrene, pt-butyl styrene, ethyl styrene vinyl naphthalene, o-methyl styrene, or two The above can be used in parallel, and preferably styrene is used alone.

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체가 그라프팅되어 있어야 한다.

,

-불포화카르본산 또는

,

-불포화무수물이나 그 유도체의 대표적인 것으로 무수말레익산, 무수이타콘산, 무수시트라콘산, 아크릴산, 메타크릴산, 알릴숙신산, 2-디카르본산, 말레인산, 푸말산, 말레인산디에틸, 말레인산디메틸, 말레산 무수물, 이타콘산 무수물, 시트라콘산 무수물, 알릴숙신산 무수물 등이 있으며, 이중에서 특히 바람직한 것은 무수말레익산이다. 또한 그라프팅 정도는 폴리페닐말레이미드 공중합체 100중량부 기준으로 0.5∼5중량부 정도가 적당하다. 그라프팅정도가 0.5중량부 미만의 경우 폴리아미드 수지와 상용성이 저하되어 내충격성, 강성의 저하를 초래하고 도장성능의 문제점이 있으며 5중량부 초 과의 경우 상용성은 우수하게 되나 급격한 점도 상승으로 혼련상의 문제 야기와 최종 조성물에 있어서 성형시 가스 발생이 많아 제품 표면에 플로우마크, 은조와 같은 문제가 생길 우려가 있어 바람직하지 않다. On the other hand, polyphenylmaleimide copolymers are not compatible with polyamide resins.

,

Unsaturated carboxylic acids or

,

-Unsaturated anhydride or derivatives thereof must be grafted.

,

Unsaturated carboxylic acids or

,

Typical examples of unsaturated anhydrides and derivatives thereof include maleic anhydride, itaconic anhydride, citraconic anhydride, acrylic acid, methacrylic acid, allyl succinic acid, 2-dicarboxylic acid, maleic acid, fumaric acid, diethyl maleate, dimethyl maleate, and maleic acid. Acid anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, and the like, of which maleic anhydride is particularly preferred. In addition, the grafting degree is suitable about 0.5 to 5 parts by weight based on 100 parts by weight of the polyphenylmaleimide copolymer. If the grafting degree is less than 0.5 parts by weight, the compatibility with the polyamide resin is lowered, resulting in a drop in impact resistance and rigidity, and there is a problem of coating performance. It is not preferable because there is a problem of kneading and the gas generated during molding in the final composition may cause problems such as flow marks and silver bath on the surface of the product.

The number average molecular weight of the polyphenylmaleimide copolymer is preferably 80,000 to 200,000. If the number average molecular weight is less than 80,000, the impact strength and flexural modulus effects are insignificant.

The preferred content of the second modifier in the composition is 5-20% by weight. If less than 5% by weight, not only the effect of the rigidity and impact resistance is insufficient, but also lacks the primer-free coating performance is not preferable, and if it is more than 20% by weight it is difficult to melt kneading and increases the cost,

The third modifier of the composition is a primer-free coating modifier, in the form of a core-shell, in which an oxirane-containing unsaturated compound is a rubber component consisting of an acrylic rubber or a diene rubber and an unsaturated compound graftable to the rubber component. Copolymerized with the copolymer. More specifically, the third modifier is a core-shell form consisting of 35 to 65% by weight of a rubber component consisting of acrylic rubber or diene rubber and 10 to 60% by weight of an unsaturated compound graftable to the rubber component. 1-8 wt% of an silane group-containing unsaturated compound is copolymerized with the copolymer of. Such a copolymer is prepared by a conventional emulsion polymerization method, and each component will be described in detail as follows. First, the core component includes an acrylic rubber or diene rubber component. Examples of the acrylic rubber component include ethyl acrylate, propyl acrylate, and butyl acrylate. Examples of the diene rubber component include butadiene, isoprene, chloroprene and cyanobutadiene, among which butadiene is particularly preferable.

In the third modifier of the present invention, when the core component is used in an amount of 35 to 65% by weight based on the total core shell elastomer, the content of the core component is less than 35% by weight. There is a problem that there is a problem that the graft efficiency decreases due to less chance, and there is an unreacted shell component, and when it exceeds 65% by weight, there is a problem that causes heat resistance and fluidity of the final composition in the final composition.

The compound which forms a shell is an unsaturated compound graftable to the rubber which is a core component. Such unsaturated compounds include methyl methacrylate, N-phenylmaleimide, methacrylonitrile, butyl methacrylate, and the like, and two or more selected from these monomers can be used to form a copolymer, which is particularly preferred. Is methyl methacrylate. In the third modifier of the present invention, it is preferable to use the shell component in an amount of 10 to 60% by weight based on the entire core shell component, and the reason is that if the amount is less than 10% by weight, the core component is relatively large, resulting in poor heat resistance and fluidity. This is because there is a problem in that the graft efficiency with the core component is lowered when used in excess of 60% by weight.

 In addition, the third modifier of the present invention is introduced into the core-shell copolymer for introducing an oxysilane group-containing unsaturated compound for synergistic effect with polyamide and synergistic paintability. Examples of such an oxysilane group-containing unsaturated compound include 1,2-epoxy-7-octane, glycidyl methacrylate, thioglycidyl acrylate, and the like, of which glycidyl methacrylate is particularly preferred. In the third modifier, the oxirane group-containing unsaturated compound is preferably 1 to 8% by weight, because when used at less than 1% by weight, there is a problem that the effect as a compatibilizer is insufficient and used in excess of 8% by weight. The lower the flow index of the resin, which is not preferable. Particularly preferred third modifiers are copolymers comprising 35 to 65% by weight of butadiene as core, 10 to 60% by weight of chelomethyl methacrylate and 1 to 8% by weight of glycidyl methacrylate as oxirane material.

The content of the third modifier in the composition is 1 to 5% by weight is appropriate. If the content is less than 1% by weight, the desired compatibility effect and paintability effect are insufficient, and if the content is more than 5% by weight, the flow index of the resin is low, there is a disadvantage in poor fluidity.

As the fourth modifier, a styrene maleic anhydride copolymer grafted with maleic anhydride is used as the fourth modifier. As described above, maleic anhydride has excellent reactivity with a functional group that is excellent in reactivity with the polyamide resin, that is, an amide group. The fourth modifier can be prepared by copolymerizing such maleic anhydride with styrene. At this time, maleic anhydride is in the range of 0.5 to 10% by weight outside the above range, the difference in the viscosity of the share is not meet the desired purpose. This copolymer can be prepared by conventional emulsion, suspension polymerization, which is known. This copolymer not only has excellent reactivity with the amide functional group of the polyamide resin, but also improves compatibility with other materials such as a second modifier or a third modifier, maximizes mechanical properties, and also delays the rate of solidification. It not only plays a role of obtaining a good appearance of the molded product, but also serves to reduce the difference in the share viscosity between the gate part of the molded part and the final filling area, thereby obtaining a product having a good surface. In the present composition, the content of the fourth modifier is 0.2 to 0.6, and when the amount is less than 0.2 wt%, the effect is insignificant. It causes strength weakness.

In addition to the above-described modifiers, other materials, such as heat-resistant and weather-resistant agents, may be used within the scope of not impairing the object of the present invention. In the present invention, the heat-resistant agent is tris- (2,4) having an amide group. Iganox B1171 (brand name, manufacturer: sea bergide) which is a 1: 1 mixture of -dibutylbutylphenyl) -phosphate and N-N'-hexamethylenebis (3.5-dibutylbutyl-4-hydroxy-hydrocinamide) As a light stabilizer, which is a resin composition using), and which absorbs ultraviolet rays, hydroxyphenyl benzotriazolotinubin 234 (trade name, manufacturer: Seabagei) and scavenged peroxide decomposing agent and radicals generated by ultraviolet Another substance that functions as a lowering agent is tinuvin 777, a light stabilizer of a hindered amine system having a tetra-methyl-piperidine structure. The composition is used to page),

An extruder can be used to manufacture the polyamide resin composition of this invention. For example, a twin screw extruder can be used to produce cylinder barrels at temperatures between 270 ° C. and 280 ° C. (for polyamide 66) or 245 ° C. to 260 ° C. (for polyamide 6) to maximize the properties of the resin composition. In order to use an extruder with three inlets, polyamide resin, third and fourth modifiers, heat-resistant agents, and weathering agents are added to the first inlet, the first reformer to the second inlet, and the second reformer to the third inlet. It is preferable to inject. A pressure reducing device called vent is provided near the discharge part, and it is effective to reduce the pressure to 150 mmHg or less.

Hereinafter, the present invention will be described in more detail by dividing the examples and comparative examples as follows, but the present invention is not limited by the examples, and the composition of the resin to be prepared accordingly is based on the following evaluation criteria. Was evaluated.

 (Assessment Methods)

* Impact strength: According to ASTM D256, Izod Notched impact strength of 3.2mm thick test specimen was measured at room temperature.

* Flexural modulus: measured by using 3.2mm thick test specimen according to ASTM D790

* Forming: The mold temperature is controlled at room temperature with a clamping force of 150 tons Nisisa injection machine for the cavity as shown in Figs. 1 to 3, and the injection temperature is 2 bar and 2 bar without pressure of 60 bar and 40 bar, respectively. , Injection time 3 seconds, cooling time 10 seconds Injection speed 1st 30%, 2nd 40%, 3rd 45%, 4th 40%

 * Paintability: Figure 1 manufactured for the evaluation of the formability 1) the product was evaluated the paintability without the primer treatment in the following process.

Coating process: To remove dust and dirt on the surface of the product, perform surface cleaning with isopropyl alcohol, and mix 50 parts by weight of thinner or 65 parts by weight of hardener with 100 parts by weight of the main component of the urethane-based two-component paint, and spray it on the surface. 20 to 30um thick and then dried at 90 ° C. for 45 minutes. Next, a top ratio of 100 parts by weight of a urethane-based two-component clear paint was added in an amount of 10 parts by weight of a curing agent and 70 parts by weight of thinner. Also, the spray method was applied to a thickness of 25 to 35um and dried at 80 ° C. for 30 minutes to secure and evaluate the coated product.

Paintability rating:

1) Adhesion: Finished painting with 100 mm or more 1mm checkerboard scales, apply polypropylene adhesive tape (product of Deokcheon Chemical Co., Ltd.) and peel off using instantaneous force

2) Evaluation of adhesion after heat cycle resistance: 120 ℃ × 3 hours-> room temperature × 1 hour-> -30 ℃ × 3 hours-> room temperature × 1 hour-> 50 ℃ 98% RH x 15 hours- > After 5 cycles of 1 cycle at room temperature × 1 hour, the coating defects (color change, cracking, peeling, etc.) are examined. In case of color change, the "b" value is evaluated by using a color meter. Was increased above 0.2, it was judged to be defective, and in case of cracking and peeling, it was visually evaluated to evaluate the defect of coating film.

3) Evaluation of hot water resistance: After immersion in distilled water at 40 ° C for 240 hours, swelling and discoloration of the coating film were visually observed.

[Examples 1-20]

The composition shown in Table 3 was melt kneaded in a twin screw extruder heated to 275 ° C. (for polyamide 66) or 250 ° C. (for polyamide 6) to make a chip state, and then to 90 ° C. for 6 hours. After drying using the heated screw-type injection molding machine using the same temperature as the melt kneading was prepared in accordance with the ASTM standards for evaluation and moldability evaluation specimens were evaluated by the above evaluation method. The evaluation results are presented in Table 4.

 division Ingredients (% by weight) Polyamide 66 Polyamide 6 First modifier Secondary modifier Tertiary modifiers Fourth modifier room                                                                                                    city                                                                                                    Yes One 76.8 10 10 (# 1) 3 (# 4) 0.2 (# 6) 2 74.7 12 12 (# 2) 1 (# 5) 0.3 (# 6) 3 77.4 10 10 (# 1) 2 (# 5) 0.6 (# 7) 4 74.5 5 15 (# 2) 5 (# 4) 0.5 (# 6) 5 78.8 10 8 (# 3) 3 (# 4) 0.2 (# 7) 6 78.5 15 5 (# 1) 1 (# 5) 0.5 (# 6) 7 76.7 8 10 (# 3) 5 (# 5) 0.3 (# 6) 8 76.7 12 8 (# 2) 3 (# 4) 0.3 (# 7) 9 69.8 10 17 (# 2) 3 (# 4) 0.3 (# 6) 10 60.8 15 20 (# 2) 4 (# 5) 0.2 (# 6) 11 87.7 5 5 (# 1) 2 (# 4) 0.3 (# 7) 12 76.6 10 10 (# 1) 3 (# 4) 0.4 (# 6) 13 77.7 10 10 (# 1) 2 (# 5) 0.3 (# 7) 14 74.5 5 15 (# 2) 5 (# 4) 0.5 (# 6) 15 78.5 10 8 (# 3) 3 (# 4) 0.5 (# 7) 16 78.4 15 5 (# 1) 1 (# 5) 0.6 (# 7) 17 76.7 8 10 (# 3) 5 (# 5) 0.3 (# 7) 18 69.7 10 17 (# 2) 3 (# 4) 0.3 (# 6) 19 61.6 15 20 (# 2) 3 (# 5) 0.4 (# 6) 20 87.5 5 5 (# 1) 2 (# 4) 0.4 (# 7)

(# 1): maleic anhydride (1.5 parts by weight) grafted phenylmaleimide (50% by weight) styrene (50% by weight)

(# 2): maleic anhydride (3 parts by weight) grafting phenylmaleimide (45% by weight) styrene (55% by weight)

(# 3): maleic anhydride (4 parts by weight) grafting phenylmaleimide (55% by weight) styrene (45% by weight)

(# 4): glycidyl methacrylate (5% by weight) butadiene (45% by weight) methyl methacrylate (50% by weight)

(# 5): glycidyl methacrylate (2% by weight) butadiene (38% by weight) methyl methacrylate (60% by weight)

(# 6): maleic anhydride (1% by weight) styrene (99% by weight)

(# 7): maleic anhydride (7% by weight) styrene (93% by weight)

 division Impact strength (kgcm / cm) Bend MD (kg / ㎠) Formability Paintability  Flow mark  Silver  Adhesion (Extract 100 out of 100) Heat cycle resistance Hot water resistance Color change ("b" change) Gala Park Lee Bloat Discoloration room                                                                                                    city                                                                                                    Yes One 61 21,700 ◎ ◎ 0 0.08 ◎ ◎ ◎ ◎ 2 83 22,150 ◎ ◎ 0 0.13 ◎ ◎ ◎ ◎ 3 67 22,100 ◎ ◎ 0 0.09 ◎ ◎ ◎ ◎ 4 58 23,150 ◎ ◎ 0 0.05 ◎ ◎ ◎ ◎ 5 61 22,050 ◎ ◎ 0 0.15 ◎ ◎ ◎ ◎ 6 91 20,400 ◎ ◎ 0 0.13 ◎ ◎ ◎ ◎ 7 58 21,800 ◎ ◎ 0 0.09 ◎ ◎ ◎ ◎ 8 74 21,850 ◎ ◎ 0 0.12 ◎ ◎ ◎ ◎ 9 73 20,100 ◎ ◎ 0 0.11 ◎ ◎ ◎ ◎ 10 99 19,700 ◎ ◎ 0 0.13 ◎ ◎ ◎ ◎ 11 51 26,050 ◎ ◎ 0 0.11 ◎ ◎ ◎ ◎ 12 62 21,600 ◎ ◎ 0 0.12 ◎ ◎ ◎ ◎ 13 61 20,600 ◎ ◎ 0 0.09 ◎ ◎ ◎ ◎ 14 49 22,400 ◎ ◎ 0 0.03 ◎ ◎ ◎ ◎ 15 52 20,900 ◎ ◎ 0 0.17 ◎ ◎ ◎ ◎ 16 83 19,950 ◎ ◎ 0 0.10 ◎ ◎ ◎ ◎ 17 50 20,250 ◎ ◎ 0 0.08 ◎ ◎ ◎ ◎ 18 60 20,000 ◎ ◎ 0 0.10 ◎ ◎ ◎ ◎ 19 95 19,050 ◎ ◎ 0 0.18 ◎ ◎ ◎ ◎ 20 48 24,500 ◎ ◎ 0 0.05 ◎ ◎ ◎ ◎

* Formability, cracking, peeling, swelling, discoloration: ◎-> Good, X-> Poor

Comparative Examples 1 to 6

In the case where one component is excluded from the resin composition, the composition is as shown in Table 5, and manufactured in the same manner as in Example to prepare a test specimen to evaluate the physical properties and the results are shown in Table 6.

 division Ingredients (% by weight) Polyamide 66 Polyamide 6 First modifier Secondary modifier Tertiary modifiers Fourth modifier ratio                                                  School                                                  Yes One 79.7 10 10 (# 1) - 0.3 (# 6) 2 86.7 - 15 (# 2) 3 (# 4) 0.3 (# 7) 3 86.8 10 - 3 (# 5) 0.2 (# 6) 4 79.8 10 10 (# 2) - 0.2 (# 7) 5 86.6 - 15 (# 3) 3 (# 4) 0.4 (# 7) 6 86.7 15 - 3 (# 5) 0.3 (# 6) 7 75 12 10 (# 1) 3 (# 4) - 8 75 10 12 (# 3) 3 (# 5) -

(# 1): maleic anhydride (1.5 parts by weight) grafted phenylmaleimide (50% by weight) styrene (50% by weight)

(# 2): maleic anhydride (3 parts by weight) grafting phenylmaleimide (45% by weight) styrene (55% by weight)

(# 3): maleic anhydride (4 parts by weight) grafting phenylmaleimide (55% by weight) styrene (45% by weight)

(# 4): glycidyl methacrylate (5% by weight) butadiene (45% by weight) methyl methacrylate (50% by weight)

(# 5): glycidyl methacrylate (2% by weight) butadiene (38% by weight) methyl methacrylate (60% by weight)

(# 6): maleic anhydride (1% by weight) styrene (99% by weight)

(# 7): maleic anhydride (7% by weight) styrene (93% by weight)

division Impact strength (kgcm / cm) Bend MD (kg / ㎠) Formability Paintability Flow mark Joe Adhesion (Extract 100 out of 100) Heat cycle resistance Hot water resistance Color change ("b" change) Gala Park Lee Bloat Discoloration ratio                                                  School                                                  Yes One 64 21,500 ◎ ◎ 5 0.16 X X ◎ ◎ 2 10 26,900 X ◎ 0 0.06 ◎ ◎ ◎ ◎ 3 49 17,800 X X 0 0.02 ◎ ◎ X X 4 68 20,900 ◎ ◎ 3 0.17 X X ◎ X 5 9 26,080 X X 0 0.07 ◎ ◎ ◎ ◎ 6 51 17,010 X X 0 0.05 ◎ ◎ X X 7 43 20,300 X ◎ 4 0.15 X ◎ ◎ X 8 41 19,800 X ◎ 2 0.19 X ◎ ◎ X

* Formability, cracking, peeling, swelling, discoloration: ◎-> Good, X-> Poor

Comparative Example 9-19

The same procedure as in Example 1 was repeated except that the composition of the polyamide resin composition was changed as shown in Table 7. Physical property evaluation results for each composition are shown in Table 8.

division Ingredients (% by weight) Polyamide 66 Polyamide 6 First modifier Secondary modifier Tertiary modifiers Fourth modifier Comparative Example 9 84.7 3 10 (# 1) 2 (# 4) 0.3 (# 6) 10 77.7 17 12 (# 2) 3 (# 4) 0.3 (# 7) 11 85.8 10 3 (# 3) 3 (# 5) 0.2 (# 6) 12 60.8 10 27 (# 2) 2 (# 5) 0.2 (# 7) 13 72 12 15 (# 3) 0.5 (# 4) 0.5 (# 7) 14 76.7 15 12 (# 1) 6 (# 5) 0.3 (# 6) 15 74.9 12 10 (# 1) 3 (# 4) 0.1 (# 6) 16 74.3 10 12 (# 3) 3 (# 5) 0.7 (# 7) 17 74.7 10 12 (a) 3 (# 5) 0.3 (# 7) 18 74.7 10 12 (# 2) 3 (b) 0.3 (# 6) 19 72.7 12 12 (# 1) 3 (# 4) 0.3 (c)

(# 1): maleic anhydride (1.5 parts by weight) grafted phenylmaleimide (50% by weight) styrene (50% by weight)

(# 2): maleic anhydride (3 parts by weight) grafting phenylmaleimide (45% by weight) styrene (55% by weight)

(# 3): maleic anhydride (4 parts by weight) grafting phenylmaleimide (55% by weight) styrene (45% by weight)

(# 4): glycidyl methacrylate (5% by weight) butadiene (45% by weight) methyl methacrylate (50% by weight)

(# 5): glycidyl methacrylate (2% by weight) butadiene (38% by weight) methyl methacrylate (60% by weight)

(# 6): maleic anhydride (1% by weight) styrene (99% by weight)

(# 7): maleic anhydride (7% by weight) styrene (93% by weight)

(a): maleic anhydride (0.2 parts by weight) grafted phenylmaleimide (45% by weight) styrene (55% by weight)

(b): glycidyl methacrylate (0.5% by weight) butadiene (45% by weight) methyl methacrylate (50% by weight)

(c): maleic anhydride (0.2 wt%) styrene (93 wt%)

division Impact strength (kgcm / cm) Bend MD (kg / ㎠) Formability Paintability Flow mark Joe Adhesion (Extract 100 out of 100) Heat cycle resistance Hot water resistance Color change ("b" change) Gala Park Lee Bloat Discoloration Comparative Example 9 13 28,500 ◎ ◎ 0 0.22 X X ◎ ◎ 10 95 16,900 ◎ ◎ 3 0.41 ◎ X X X 11 45 17,000 X X 3 0.22 ◎ X ◎ ◎ 12 68 28,900 ◎ ◎ 4 0.30 X X ◎ ◎ 13 49 26,180 ◎ ◎ 8 0.08 X X X X 14 51 24,010 X X 0 0.35 ◎ ◎ X X 15 38 22,300 X ◎ 6 0.15 X X X X 16 51 20,600 X ◎ 0 0.42 X ◎ ◎ ◎ 17 42 18,300 X ◎ 0 0.15 X ◎ X X 18 54 24,030 ◎ X 7 0.11 X X X X 19 54 24,950 ◎ ◎ 8 0.10 X X X X

* Forming, cracking, peeling, swelling, discoloration: ◎-> Good, X-> Poor

Comparative Example 20-21

Acrylonitrile butadiene styrene resin of Comparative Example 20 (acrylonitrile / butadiene / styrene = 25/30/45% by weight) and polyphenylene ether and polystyrene alloy of Comparative Example 21 as a commercialized resin having coating performance without primer process. Test specimens were prepared in the same manner as in Example 1 for resins (trade names: NORYL, GE Corporation), and physical properties were evaluated. The evaluation results are shown in Table 9.

division Impact strength (kgcm / cm) Bend MD (kg / ㎠) Formability Paintability Flow mark Joe Adhesion (Extract 100 out of 100) Heat cycle resistance Hot water resistance Color change ("b" change) Gala Park Lee Bloat Discoloration Comparative example 20 25 18,300 ◎ X 0 0.55 ◎ ◎ ◎ X 21 18 21,200 X ◎ 0 0.61 ◎ ◎ ◎ X

* Forming, cracking, peeling, swelling, discoloration: ◎-> Good, X-> Poor

As described above, the polyamide resin composition of the present invention is not only paintable without primer, but also has excellent impact strength, rigidity, moldability, heat resistance, water resistance, etc., and reduces the production cost of the product in the existing painting method. It is a composition which can be used, and it is a composition which has the characteristic outstanding effect in the weld line, flow mark, silver bath etc. which arise in injection molding. Therefore, products that require impact resistance, rigidity, and products that require excellent paint performance, such as automotive exterior goods such as wheel covers, wheel caps, fuel inlet lids, outdoor handles, etc. It is suitable for products and can be usefully applied to outdoor park chairs and stadium chairs as daily necessities.

Claims (7)

In the polyamide resin composition, based on 60.8 to 87.7% by weight of the polyamide resin which is the base resin and the total weight of the composition, (a) Ethylene as the first modifier,

-Copolymers of copolymerizable compounds selected from the group consisting of olefins, acrylic acid or derivatives thereof, aromatic vinyl monomers and vinyl cyanide monomers with olefin monomers

,

Unsaturated carboxylic acids or

,

5 to 15% by weight of a thermoplastic rubber elastomer grafted with an unsaturated anhydride or a derivative thereof; (b) a polyphenylmaleimide copolymer copolymerized with phenylene maleimide and an aromatic vinyl compound as a second modifier;

,

Unsaturated carboxylic acids or

,

5 to 20% by weight of grafted unsaturated anhydrides or derivatives thereof; (c) 1 to 5% by weight of an oxysilane-containing unsaturated compound copolymerized with a rubber component consisting of an acrylic rubber or a diene rubber as a third modifier and a core-shell copolymer comprising an unsaturated compound graftable to the rubber component and (d) 0.2 to 0.6% by weight of styrene maleic anhydride copolymer grafted with maleic anhydride as a fourth modifier. The polyamide resin composition according to claim 1, wherein the polyamide resin is a polyamide 66 resin or a polyamide 6 resin. The polyamide resin composition according to claim 1, wherein the first modifier is an ethylene propylene copolymer grafted with 0.4 to 10% by weight of maleic anhydride. According to claim 1, wherein the second modifier is 0.5 to 5 parts by weight of maleic anhydride based on 100 parts by weight of the polyphenyl maleimide styrene copolymer copolymerized with phenylene maleimide and styrene 40 to 60% by weight, respectively. A polyamide resin composition characterized in that the copolymerized copolymer having a number average molecular weight of 80,000 to 200,000. The method of claim 1, wherein the third modifier is a copolymer consisting of 35 to 65% by weight of butadiene as the core, 10 to 60% by weight of methyl methyl methacrylate as the core, and 1 to 8% by weight of glycidyl methacrylate as the oxirane material. A polyamide resin composition characterized by the above. The polyamide resin composition according to claim 1, wherein the fourth modifier is a styrene maleic anhydride copolymer grafted with 0.5 to 10% by weight of maleic anhydride. delete

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