JPH01129012A - Molding material - Google Patents

Abstract

PURPOSE:To obtain a molding material excellent in moldability, transparency, mechanical properties, heat resistance and impact resistance, by incorporating a methacrylate polymer in a thermoplastic wholly aromatic polyester. CONSTITUTION:0.1-20mul, per g of polyester, of an unsaturated amine (e.g., allylamine) is added to a solution of 0.05-0.2g/ml of a thermoplastic wholly aromatic polyester of a weight-average MW of 15000-100000 in tetrahydrofuran and reacted to introduce reactive vinyl groups into the terminals of the polyester. A methacrylate monomer in an amount to give a methacrylate polymer content of 10-80wt.% is added to the above product and polymerized at 60-110 deg.C for 2-10hr in the presence of a polymerization catalyst in an inert gas atmosphere to obtain a molding material comprising a thermoplastic modified aromatic polyester resin which is a thermoplastic wholly aromatic polyester/ methacrylate polymer (weight-average MW of 50000-500000) block copolymer.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a molding material that has excellent moldability and whose molded products have excellent impact resistance and heat resistance. .

(Prior art and its problems) Methacrylic resin whose main component is methyl methacrylate is
It has excellent optical properties and weather resistance, and has a good balance of mechanical properties, thermal properties, and moldability, making it suitable for signboards, lighting covers, nameplates, automobile parts, and decorative items. It is widely used in fields such as

However, methacrylic resin, for example, has a heat distortion temperature of 10
At present, its application fields are limited because its heat resistance is not sufficient, such as being around 0°C, and its Izot impact strength is not sufficient, being around 5 kgf/cta/crs. Therefore, it is desired to improve the heat resistance and impact resistance of methacrylic resins.

For information on how to improve the heat resistance of methacrylic acid resin,
Many proposals have been made. For example, a method of copolymerizing methyl methacrylate and α-methylstyrene, a method of copolymerizing methyl methacrylate, α-methylstyrene, and maleic anhydride (see Japanese Patent Publication No. 10156/1983). ), a method of copolymerizing methyl methacrylate, styrene, and maleic anhydride (see Japanese Patent Publication No. 56-43242), a method of copolymerizing methyl methacrylate, α-methylstyrene, styrene, and maleic anhydride (see Japanese Patent Publication No. 56-43242); 5
6-81322), a method of dissolving poly-α-methylstyrene in methyl methacrylate and then polymerizing methyl methacrylate (see Japanese Patent Publications No. 43-1616 and Japanese Patent Publication No. 49-8718), methacrylic A method for copolymerizing methyl methacrylate and N-allylmaleimide (see Japanese Patent Publication No. 43-9753), a method for copolymerizing methyl methacrylate, α-methylstyrene, and N-phenylmaleimide, and a method for copolymerizing polyfunctional monomers. A method of copolymerizing methyl methacrylate in the presence of a crosslinked polymer using a polymer is known.

(Problems to be Solved by the Invention) Although the above-mentioned conventional technology improves heat resistance, the polymerization rate is extremely slow, resulting in extremely low productivity.
It is industrially disadvantageous, and is still unsatisfactory in that mechanical properties and weather resistance deteriorate, molded products are colored, and impact resistance remains low.

Therefore, the present invention solves the above problems and maintains the excellent transparency, mechanical properties, moldability, etc. that methacrylic acid resin originally has, while improving impact resistance and heat resistance. The purpose of the present invention is to provide a molding material that allows molded products with excellent properties to be obtained.

[Structure of the invention] (Means and effects for solving the problems) The molding material of the present invention is a thermoplastic modified aromatic polyester which is a block copolymer of a thermoplastic wholly aromatic polyester and a methacrylic acid ester polymer. A molding material made of resin, characterized in that the content of the methacrylic acid ester polymer in the thermoplastic, property-modified aromatic polyester resin is 10 to 80% by weight.

The thermoplastic modified aromatic polyester resin constituting the molding material of the present invention can be produced by reacting a thermoplastic wholly aromatic polyester with a methacrylic acid ester monomer or a methacrylic acid ester polymer and chemically bonding it. Can be done.

The thermoplastic wholly aromatic polyester (hereinafter simply referred to as "wholly aromatic polyester") used in the production of thermoplastic modified aromatic polyester resin is obtained by reacting an aromatic dicarboxylic acid with an aromatic dihydroxy compound. It is a polymer that can be used.

Examples of the aromatic dicarboxylic acid used here include terephthalic acid, isophthalic acid, nuclear halogen-substituted terephthalic acid, and isophthalic acid, and among these, terephthalic acid and isophthalic acid are preferred.

As the aromatic dihydroxy compound, 2,2-bis(4
-Hydroxyphenyl)propane (hereinafter abbreviated as "bisphenol A"), tetramethylbisphenol A
, tetrabromobisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, [/zorcinol, 4,4'-dihydroxydiphenyl, etc., among which bisphenol A is particularly preferred.

The wholly aromatic polyester preferably has a weight average molecular weight of 15,000 to Zoo,000 as measured by gel permeation chromatography (GPC).

As wholly aromatic polyester, commercially available ゛°U
Polymer rU-100J” (product name, manufactured by Unitika)
can be exemplified.

Examples of methacrylic acid ester monomers reacted with fully aromatic polyesters in the production of thermoplastic modified aromatic polyesters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and n-methacrylate.
Examples include butyl, isobutyl methacrylate, and methyl methacrylate is preferably used. These methacrylic acid ester monomers can be used alone or in combination of two or more.

In addition, when producing the thermoplastic modified aromatic polyester, if necessary, other unsaturated monomers copolymerizable with the methacrylic acid ester monomer may be added alone or in combination in an amount not exceeding 10% by weight of the total monomer usage. Can be used together. Examples of such unsaturated monomers include styrene, α-methylstyrene, p-methylstyrene, acrylonitrile, and methyl acrylate.

The methacrylic acid ester polymer used in the production of thermoplastic modified aromatic polyester is 1. 1: Can be obtained by polymerizing the styrene monomer shown below and other monomers as necessary.

The weight average molecular weight of the methacrylic acid ester polymer as measured by GPC is preferably within the range of 50,000 to 500,000.

If the molecular weight is too small, the mechanical properties of the resulting molding material will deteriorate, and if the molecular weight is too large, the moldability of the resulting molding material will deteriorate, which is undesirable.

Next, the method for producing the thermoplastic modified aromatic polyester constituting the molding material of the present invention will be described with reference to two production examples.

(1) First, allylamine is added to a fully aromatic polyester dissolved in tetrahydrofuran and reacted to introduce a reactive vinyl group to the end of the fully aromatic polyester, and then a methacrylic acid ester A method of adding a monomer and polymerizing it can be mentioned.

Fully aromatic polyesters are unstable in the presence of basic compounds, and the main chain is easily cleaved especially in the presence of alkalis or organic amines. However, unsaturated organic amines such as allylamine By allowing an amine having a carbon double bond to be present in the reaction system, a reactive vinyl group can be introduced to the cut end of the main chain. The amount of allylamine used in this method is O01 to 20 allylamine per Ig of fully aromatic polyester.
It is preferable to be in the range of ILl/g. If this value is too small, the yield of the thermoplastic modified aromatic polyester resin will be low, and if it is too large, the yield of the thermoplastic modified aromatic polyester resin will be reduced. Because the fully aromatic polyester chain of is too short, the impact resistance of the molding material decreases.

For the fully aromatic polyester and allylamine, add the fully aromatic polyester to tetrahydrofuran at O,OS~0.2g/
A predetermined amount of allylamine was added to the solution dissolved in the ratio of mu, and after stirring, the mixture was heated at 90°C in an autoclave.
Then, a methacrylic ester monomer was added to the reaction solution in an amount such that the content of the methacrylic ester polymer after polymerization was from 10 to 80% by weight, and the inside of the reaction system was heated with nitrogen gas. After the substitution, a polymerization reaction is carried out at 90°C for 7 hours.A polymerization catalyst is used in this polymerization reaction.Any catalyst can be used as long as it dissolves in the methacrylic acid ester monomer. , for example, benzoyl peroxide, azobisisobutyronitrile, etc. are preferred.

After one reaction is completed, the produced thermoplastic modified aromatic polyester is separated, washed, and then dried.

(2) The other method is to add and mix a predetermined amount of allylamine to a methacrylate monomer, perform a polymerization reaction, and then mix the resulting methacrylate monomer and wholly aromatic polyester in a predetermined ratio. A method of melt-mixing can be mentioned.

The mixing ratio of methacrylic acid ester monomer and allylamine is methacrylic acid ester monomer/-F-Zoo weight 1
The amount of allylamine is preferably 0 and 1 to 0.1 parts by weight based on B. If the amount of allylamine is too small, the yield of thermoplastic modified aromatic polyester will be low, and if it is too large, methacrylic This is not preferred because the polymerization rate of the acid ester monomer becomes slow and the thermoplastically modified aromatic polyester is crosslinked.

During the polymerization reaction, the above-mentioned polymerization catalyst is added and the reaction system is replaced with nitrogen gas. The zero polymerization is carried out at 60-110° C. for 2-10 hours.

Melt mixing of the obtained methacrylic acid ester polymer and wholly aromatic polyester is carried out at 260 to 340°C.
By melt-mixing in this way, the amino groups derived from allylamine in the methacrylic ester polymer chemically bond the methacrylic ester polymer to the polyester chain while partially cleaving the polyester chain. A thermoplastically modified aromatic polyester can be produced. Note that the method for producing the thermoplastic modified aromatic polyester is not limited to the above method, nor is it limited to the use of allylamine.

The content of the methacrylic acid ester polymer in the thermoplastic modified aromatic polyester thus obtained is 10
~80% by weight, preferably 20-50% by weight. If this content is 10% by weight without swirling, a molding material with good moldability cannot be obtained, and 80% by weight
If it exceeds , impact resistance and heat resistance cannot be sufficiently improved.

In addition, thermoplastic modified aromatic polyester resin is
The weight average molecular weight by method is 70.000~soo,oo
o, preferably from 70.000 to 200.000; if the molecular weight is too small, the mechanical properties of the molding material after molding will deteriorate; if it is too large, the moldability will deteriorate. is unfavorable because it reduces

The thermoplastic modified aromatic polyester is a block copolymer of a wholly aromatic polyester and a methacrylic acid ester polymer, that is, the image constituent components are chemically bonded. Originally, fully aromatic polyester and methacrylic acid ester polymer have poor compatibility, so if the two components are simply mixed, a homogeneous molding material cannot be obtained. However, as mentioned above, the polymer used in the present invention In the thermoplastic modified aromatic polyester, such a problem does not occur because the wholly aromatic polyester and the methacrylic acid ester polymer exist in a chemically bonded state.

The molding material of the present invention is composed of such a thermoplastic modified aromatic polyester, but if necessary, a fully aromatic polyester and/or a methacrylic acid ester polymer that is not chemically bonded may be added during production. It can also be present in an amount of 25% by weight or less, either as an unreacted product or as an additive after production.

In addition, in the molding material of the present invention, phosphite esters and hhindant phenols are added to the resin in order to prevent coloration and decrease in transparency due to thermal decomposition of the thermoplastic modified aromatic polyester. It can be blended in an amount of 0.01 to 1% by weight.

Examples of the phosphites used here include triphenyl phosphite, tridecyl phosphite, tributyl phosphite, tris(2-ethylhexyl) phosphite, and tricresyl phosphite. Hindant phenols include 2,6-tert-butyl, 4-methylphenol, Ionox-100.330 (trade name; manufactured by Shell Chemical ■),
Irganox-245,1076 (product name: manufactured by Ciba Geigy), Dopanol-CA (product name: I.C.Φ
For example, Yoshinox-BB (FT1 product name: manufactured by Yoshitomi Pharmaceutical Co., Ltd.) may be used.

Methods for blending such phosphite esters into thermoplastic modified aromatic polyesters include, for example, the triblend method, the method of melt-mixing when pelletizing with an extruder, and the method of blending phosphite esters with the thermoplastic modified aromatic polyester by the above-mentioned melt-mixing method. A method can be applied in which a master pellet having a high content of esters, etc. and pellets made only of thermoplastic modified aromatic polyester containing no phosphite esters are produced, and the two are triblended.

(Example) Hereinafter, the present invention will be described in more detail with reference to Examples.

In addition, in the following, both "part" and "%" are based on weight.

Example 1 First, fully aromatic polyester ("U polymer rU-10
0J”; product name, manufactured by Unitika ■) 20g for 500m
300m in M beaker! Next, 50p of allylamine dissolved in 1 of tetrahydrofuran was added, and after stirring, the mixture was placed in an autoclave with an internal volume of 500mM and reacted at 90°C for 2 hours. After the reaction was completed, it was allowed to cool to room temperature. After that, put the contents into a reactor with a stirrer,
Furthermore, 20 g of methyl methacrylate and 0.05 g of azobisisobutyronitrile were charged, then the inside of the reactor was replaced with nitrogen gas, and the polymerization reaction was carried out for 7 hours in a water bath at 90 ° C. After the completion of the reaction, Methanol was added to the reaction solution to precipitate the thermoplastic modified aromatic polyester. After that, the precipitate was collected and washed with methanol, and then
After vacuum drying overnight at 0.degree. C., 39.5 g of thermoplastic modified aromatic polyester, which is the molding material of the present invention, was finally obtained.

The weight average molecular weight (according to GPC method. The same applies hereinafter) of the obtained thermoplastic modified aromatic polyester is 16.
5,000, and the content of polymethyl methacrylate (according to NMR analysis. The same shall apply hereinafter) is 50%.
Met.

Example 2 39 g of a thermoplastic modified aromatic polyester, which is a molding material of the present invention, was obtained in the same manner as in Example 1, except that the amount of allylamine used was 80 g. The weight average molecular weight of the obtained resin was tas, ooo, and the content of polymethyl methacrylate was 52%.

'Examples 3 to 5, Comparative Example 1 Various thermoplastic modified aromatic polyesters as molding materials were obtained in the same manner as in Example 1, except that the amount of methyl methacrylate used was as shown in Table 1. These yields are shown in Table 1 together with the results of Examples 1 and 2.

Table 1 Test Examples Using each of the molding materials obtained in Examples 1 to 5 and Comparative Example 1, these were extruded using a twin screw extruder (manufactured by Isuzu) to
The obtained pellets were then pelletized at ~280°C and injection molded under the following conditions.
A test piece of 2 mm in diameter was obtained. Using this test piece,
The following tests were conducted. The results are shown in Table 2.

In addition, as Comparative Example 2, methyl methacrylate/styrene =
MAS resin (manufactured by Daicel), which is a copolymer of 80720 (weight ratio), was used as Comparative Example 3. As Comparative Example 4, a copolymer of methyl methacrylate/styrene/maleic anhydride = 35/35/30 (weight ratio) was used.
After pelletizing and molding in the same manner as above, each property was tested. The results are shown in Table 2.

Injection molding conditions: Injection molding machine (manufactured by Japan Steel Works ■; V-17
-65 type screw type automatic injection molding machine), cylinder temperature 260-270℃, injection pressure 750kg/cm2. Mold temperature 70-80℃ Melt flow index (MI): ASTM D-12
38,230℃, 10kg load heat distortion temperature (HDT):
ASTM D-648 Tensile Strength and Tensile Elongation: AST
MD-638 total light transmittance: ASTM D-10
03 Color tone of molded plate Izot impact strength: ASTM D-256,178
Notched, 23°C [Effects of the Invention] The molded material of the present invention has excellent impact resistance and heat resistance.

Claims (1)

[Scope of Claims] A molding material comprising a thermoplastic modified aromatic polyester resin which is a block copolymer of a thermoplastic wholly aromatic polyester and a methacrylic acid ester polymer, wherein the thermoplastic modified aromatic polyester resin comprises: A molding material characterized in that the content of the methacrylic acid ester polymer is 10 to 80% by weight.