JPS61281106A - Amorphous aromatic random copolymer and use thereof - Google Patents

Abstract

PURPOSE:A novel copolymer, formed from aromatic monomer component units, (meth)acrylic acid component units, etc., having specific properties and capable of producing improved effect as a crystallization promoter by blending in a polyester. CONSTITUTION:A novel copolymer containing (A) 50-99.8mol% aromatic monomer component units consisting of styrene or a lower alkyl group substitution product thereof, (B) 0.2-50mol% (meth)acrylic acid component units (C) 0.2-50mol% (meth)acrylic acid salt component units and (D) 0-40mol% alkyl (meth)acrylate component units and having 2,000-300,000 number-average molecular weight (Mn) measured by the gel permeation chromatorgraphy and 1.2-15 molecular weight ditribution (Mw/Mn) and satisfying the relation expressed by the formula [X1 is the content (mol%) of the component (B) in the copolymer; X2 is the content (mol%) of the component (C) in the copolymer]. USE:A composition having improved crystallization rate, impact strength, flexural strength, heat resistance, etc., is obtained by blending in a polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel amorphous aromatic random copolymer and its uses. More specifically, by blending it with polyester such as polyethylene terephthalate,
The present invention relates to an amorphous aromatic random copolymer that has excellent effects as a nucleating agent or crystallization promoter.

[Prior Art] Conventionally, substantially linear polyesters containing ethylene terephthalate as the main constituent unit, such as polyethylene terephthalate, have excellent properties such as rigidity, heat resistance, and gas barrier properties, and have been used for films, sheets, laminates, and containers. Although it is used as a material for molding into various shapes such as, it has the disadvantage that it has a slow crystallization rate and cannot be molded at high speed. Therefore, measures such as increasing the temperature of the molding die have been adopted to improve the crystallization rate of the polyester.
There are also disadvantages such as thermal deterioration of the resin and warping of the molded product. Therefore, in order to improve the crystallization rate of the polyester and improve its mechanical properties such as bending rigidity and heat resistance,
A considerable number of proposals have been made regarding methods of incorporating various additives into the polyester. For example, these methods include methods of blending inorganic compounds such as talc, diatoms, magnesia, etc., methods of blending metal salts of aliphatic or aromatic carboxylic acids, and methods of blending ethylene/(meth)acrylic acid copolymer moieties. Neutralized products, methods of blending ionic polymers such as partially neutralized products of styrene/(meth)acrylic acid copolymers, unsaturated polyesters, polyamides, polycarbonates, waxes, olefin waxes or their modified waxes, polyethylene Methods of blending various polymers such as glycols and polyepoxy compounds have been proposed, and there are also techniques that use two or more of these blending agents together, or technologies that use these blending agents and a polyester plasticizer together. Significant proposals have been made for 2''.

However, very few molded articles made from polyester compositions having any of these formulations are excellent in any of the properties such as crystallization rate, mechanical properties, heat resistance, and heat-resistant hue.

Conventionally, a formulation using an ionic polymer as a compounding agent to improve the above-mentioned physical properties of polyester such as polyethylene terephthalate was disclosed in Japanese Patent Publication No. 45-26225.
Special Publication No. 55-47058, i-Publication No. 55-4705
No. 9, JP-A-56-145943, JP-A-Sho 5
6-145145, JP 56-127655, JP 57-162, JP 57-192
449, JP 57-192450, JP 58-63744, JP 56-19247, JP 57-8241, JP 57-98
554, JP 57-102947, JP 57-200441, JP 58-76448
No. 71750, Japanese Patent Application Laid-Open No. 1987-71750,
No. 84244, Japanese Unexamined Patent Publication No. 118848/1984,
JP-A-58-187447, JP-A-58-210
This method has been proposed in Japanese Patent Application Laid-open No. 957, Japanese Patent Application Laid-Open No. 58-217547, and the like. Among these ionic polymers, polyester containing a neutralized product of ethylene/(meth)acrylic acid copolymer is currently widely used because it has excellent crystallization speed and mechanical properties of molded products. There is. However, polyester compositions containing a neutralized product of this ethylene/(meth)acrylic acid copolymer are inferior in heat aging resistance and color, and cannot be said to be sufficient in terms of crystallization rate.

In addition, a method of blending a neutralized product of styrene/(meth)acrylic acid copolymer as an ionic polymer with polyester such as polyethylene terephthalate was proposed in 1973-26.
It is disclosed in Publication No. 225. However, there is no specific disclosure regarding the structure and physical properties of this ionic copolymer, and there is no specific disclosure regarding the physical properties of a polyester composition obtained when this ionic copolymer is blended with polyester. The examples shown in are also not accepted.

(Problems to be Solved by the Invention) The present inventors have discovered that the crystallization rate, impact strength, bending strength, rigidity, etc. can be improved by blending ethylene terephthalate, such as polyethylene terephthalate, into a polyester whose main constituent unit is ethylene terephthalate. As a result of investigating ionic copolymers that can provide polyester compositions with excellent mechanical properties, heat resistance, and heat-resistant hue, we found that an amorphous aromatic random copolymer with specific structure and physical properties was found. It was discovered that the above objectives were achieved and it became an excellent polyester compounding agent,
We have arrived at the present invention.

[Means for Solving the Problems] and [Operation] According to the present invention, an aromatic monomer component unit (al of 50 to 99.8
mol%, (meth)acrylic acid component unit (bl is 0.2 to 50 mol%, (meth)acrylate component unit (c1
is a substantially linear amorphous aromatic random copolymer formed from 042 to 50 mol% and an alkyl (meth)acrylate component unit (di is O to 50 mol%, (i) Gelbamier ion chromatography (G
The number average molecular weight (Mn) measured by P C) is in the range of 2000 to 300000, and the molecular weight distribution (axis/Mn
) is in the range of 1.2 to 15, and (ii) the content of (meth)acrylic acid component units (b) in the copolymer is X mol%, and (meth)acrylate component units When the content of (c) is X2 mol%,
An amorphous aromatic random copolymer is provided, wherein l and X2 satisfy the general formula %. A formulation for a resin is provided.

The amorphous aromatic random copolymer of the present invention comprises an aromatic monomer component unit fa) consisting of styrene or lower alkyl-substituted styrene, a (meth)acrylic acid component unit (b), and a (meth)acrylic acid component unit fa). Terpolymer formed from salt component unit (c) or aromatic monomer component unit (a) consisting of styrene or lower alkyl group-substituted styrene (meta)
Acrylic acid component unit (bl, (meth)acrylate component unit (c) and alkyl (meth)acrylate component unit f
d) is a quaternary copolymer formed from

The aromatic monomer component unit (a) constituting the amorphous aromatic random copolymer of the present invention is styrene or styrene substituted with a lower alkyl group having 4 or less carbon atoms, and specifically, Examples include styrene, α-methylstyrene, 0-vinyltoluene, m-vinyltoluene, and p-vinyltoluene. In addition, the (meth)acrylic acid component unit (bl) can indicate acrylic acid or methacrylic acid, and the (meth)acrylate component unit (c1) specifically includes the alkali metal salt of (meth)acrylic acid, alkali Earth metal salts, zinc salts, etc., for example,
Lithium acrylate, sodium acrylate, potassium acrylate, magnesium acrylate, calcium acrylate, barium acrylate, zinc acrylate, lithium methacrylate, potassium methacrylate, magnesium methacrylate, calcium methacrylate, barium methacrylate , zinc methacrylate, and the like.

Furthermore, the alkyl (meth)acrylate component unit (d) is an alkyl ester of the (meth)acrylic acid, specifically methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, Examples include stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, octyl methacrylate, and stearyl methacrylate.

The amorphous aromatic random copolymer of the present invention contains 50 to 99.8 mol%, preferably 60 to 99.8 mol% of aromatic monomer component units (a) consisting of styrene or lower alkyl group-substituted styrene (meth)acrylic acid component unit (b) is in the range of 0.2 to 50 mol%, preferably 3 to 40 mol%, (meth)acrylate component unit (cl is 0.2 The amount of the alkyl (meth)acrylate component unit (d) is in the range of 0 to 50 mol%, preferably O to 40 mol%. If the composition of each component of the aromatic random copolymer deviates from the above range, the performance of the polyester composition blended with the amorphous aromatic random copolymer will deteriorate in any case. It becomes like this.

The number average molecular weight (Mn) of the amorphous aromatic random copolymer of the present invention measured by gel permeation chromatography (GPC) is 1000 to 300000.
, preferably from 2,000 to 200,000, more preferably from 4,500 to 100,000, and the molecular weight distribution is from 1.2 to 15, preferably from 1.5 to 10.
More preferably, it is in the range of 2 to 4. If the number average molecular weight or molecular weight distribution of the amorphous aromatic random copolymer is out of the above range, in any case, the above-mentioned Performance will begin to deteriorate.

The aromatic random copolymer of the present invention is amorphous and has no melting point when measured by X-ray diffraction or differential scanning calorimetry (DSC). The softening point of the copolymer is usually 1
50 to 260°c1 preferably 190 to 240
℃ range. If the amorphous aromatic random copolymer is crystalline, the performance of the polyester composition blended with the amorphous aromatic random copolymer will deteriorate.

(Meta) in the amorphous aromatic random copolymer of the present invention
The content of acrylic acid component units (b) is Xl mol%, and the content of (meth)acrylate component units (c) is X
When it is 2 mol %, the amorphous aromatic random copolymer of the present invention satisfies the general formula %. If the amorphous aromatic random copolymer does not satisfy the above relationship, the performance of the polyester composition containing the amorphous aromatic random copolymer will decrease.

Furthermore, the solvent solubility of the amorphous aromatic random copolymer of the present invention [the amount dissolved after stirring for 16 hours in a solvent at room temperature, expressed as g/(100 mf of solvent)] is not as high as that in methanol. Usually 2 to 20 g/100 d, preferably 3 to 15 g/100 wf, and usually 0.1 g/100*f or less for water.

The amorphous aromatic random copolymer of the present invention can be produced by the method shown below.

That is, the styrene is a monomer consisting of an aromatic monomer component (a) consisting of lower alkyl group-substituted styrene, the (meth)acrylic acid component (bl, and optionally the (meth)acrylic acid ester component Cd). The copolymerization is carried out by suspending the mixture in water in the presence of a dispersant and a polymerization initiator, and generally at a temperature of 50 to 100° C. with stirring. The ratio of the monomer mixture to water during the copolymerization reaction is 1
The amount is usually 10 to 50 parts by weight, preferably 15 to 40 parts by weight. Dispersion agents include gelatin, polyacrylic acid, and polyacrylic acid N.
a. Polyvinyl alcohol is preferably used, and its usage ratio is usually 0.1 to 2.0 parts by weight per 100 parts by weight of water.
0 parts by weight, preferably in the range of 0.2 to 1.5 parts by weight.

Furthermore, as the polymerization initiator, benzoyl peroxide, azobisisobutyronitrile, and dilauroyl peroxide are preferably used, and the proportion thereof is usually 0.1 to 2.0 parts per 100 parts by weight of the monomer mixture. parts by weight, preferably in the range of 0.2 to 1.5 parts by weight.

After the copolymer produced after the polymerization reaction is separated by filtration, the copolymer is washed with water and dried to obtain a copolymer. By reacting a basic aqueous solution with a solution of the copolymer dissolved in a solvent such as benzene, toluene, or xylene at a temperature of 50 to 150°C while azeotropically removing water, the (meth) in the copolymer is removed. The amorphous aromatic random copolymer of the present invention is produced by partially neutralizing the acrylic acid component units.

At that time, the neutralization rate is usually adjusted within the range of 30 to 100 mol%, preferably 50 to 75 mol%, and the (
It is necessary that the content of the meth)acrylic acid component unit (c) be within the above range. In addition, the mixture of the copolymer powder obtained by the copolymerization reaction and the base was treated with an extruder or the like under melt mixing conditions, and the neutralization rate at that time was adjusted to be within the above range. The amorphous aromatic random copolymer of the present invention can be obtained by neutralizing so that the acid salt component unit (c) falls within the above range.

The amorphous aromatic random copolymer of the present invention is used as a compounding agent for polyester resin. The polyester resin to which the compounding agent of the present invention is blended is a substantially linear polyester containing ethylene terephthalate as a main constituent unit.

The content of ethylene terephthalate structural units in the polyester is in the range of 70 mol% or more, preferably 80 mol or more. The dicarboxylic acid component units constituting the polyester may contain a small amount of other aromatic dicarboxylic acid component units in addition to the terephthalic acid component units. Specific examples of aromatic dicarboxylic acid component units other than terephthalic acid component units include isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid. The diol component units constituting the polyester may contain small amounts of other diol component units in addition to the ethylene glycol component units.

Specifically, other diol component units other than ethylene glycol component units include propylene glycol, 1.3-
Propanediol, 1,4-butanediol, neopentyl glycol, cyclohexanediol, cyclohexane dimetatool, 1,4-bis(β-hydroxyethoxy)benzene, 1,3-bis(β-hydroxyethoxy)benzene, 2. Carbon such as 2-bis(4-β-hydroxyethoxyphenyl)propane, bis(4-β-hydroxyethoxyphenyl)sulfone, bis(4-hydroxyphenyl)methane, 2.2-bis(4-hydroxyphenyl)propane Examples include diol component units having 3 to 20 atoms and polyalkylene glycol units such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol having a molecular weight of 300 to 10,000. In addition to the aromatic dicarboxylic acid component units and the diol component units, the polyester may also contain a small amount of a polyfunctional compound as required. Specific examples of polyfunctional compound component units include aromatic polybasic acids such as trimethic acid, trimelanic acid, pyromellitic acid, 3.3', 5.5'-tetracarboxydifniel, butanetetracarboxylic acid, etc. fatty polybasic acids, phloroglucin, aromatic polyols such as 1゜2.4.5-tetrahydroxybenzene, aliphatic polyols such as glycerin, trimethylolethane, l-rimethylolpropane, pentaerythritol, tartaric acid, Examples include oxypolycarboxylic acids such as malic acid.

Further, the polyester may contain a small amount of an oxycarboxylic acid compound such as p-hydroxybenzoic acid in addition to the aromatic dicarboxylic acid component unit, the diol component unit, and the polyfunctional compound.

The composition of the constituent components of the polyalkylene terephthalate is:
The content of terephthalic acid component units is usually 40 to 51
The content of aromatic dicarboxylic acid component units other than terephthalic acid component units is usually 0 to 10 mol%, preferably 0 to 7 mol%. The content of ethylene glycol component units is usually in the range of 35 to 51 mol%,
Preferably, the content of diol component units other than ethylene glycol component units is in the range of 0 to 15 mol%, preferably O to 10 mol%, and the polyfunctional compound component. The content of units is usually in the range of 0 to 10 mol%, preferably 0 to 8 mol%. In addition, the intrinsic viscosity of the polyester [
η] (value measured at 50°C in p ~ dichloroenol solution) is usually in the range of 0.45 to 2.0 J/g, preferably 0.50 to 1.8 d7/g, and the melting point is usually The glass transition temperature is usually in the range of 40 to 140'C, preferably 50 to 120'C.

The blending ratio of the amorphous aromatic random copolymer of the present invention to the polyester is usually 0.1 to 50 g parts, preferably 0.1 to 50 g parts per 100 car weight parts of the polyester.
．． It ranges from 5 to 40 parts by weight.

The polyester resin compounding agent comprising the amorphous aromatic random copolymer of the present invention can be used in combination with other compounding agents to the extent that the effects thereof are not impaired. For example, other additives that can be used in combination include various nucleating agents, plasticizers, heat stabilizers, surfactants, thickeners, flame retardants, ultraviolet stabilizers, antioxidants, and mold release agents. Examples include agents, colorants, and various fillers. The mixing ratio of these ingredients is appropriate. Moreover, the compounding agent for polyester consisting of the amorphous aromatic random copolymer of the present invention is
Compounded into polyester resins in combination with various other polymers such as polyolefins, olefin copolymers, modified polymers thereof, polystyrene, polyamides, polycarbonates, polyacetals, polysulfones, polyphenylene oxides, fluororesins, silicone resins, epoxy resins, etc. You can also.

The compounding agent for polyester resin comprising the amorphous aromatic random copolymer of the present invention can be mixed with the polyester together with the above-mentioned optional components, and melt-kneaded according to a conventionally well-known method. .

〔Effect of the invention〕

A polyester composition in which the amorphous aromatic random copolymer of the present invention is blended with a polyester whose main constituent unit is ethylene terephthalate has a crystallization rate that is higher than that of a polyester composition blended with a conventional ionic polymer. It is said that a polyester composition with excellent mechanical properties such as impact strength, bending strength, and rigidity, heat resistance, and heat-resistant hue can be obtained, and in particular, a polyester composition with excellent crystallization speed and excellent heat resistance and heat-resistant hue can be obtained. It has characteristics.

【Example〕

Next, the present invention will be specifically explained with reference to Examples.

In the Examples and Comparative Examples, the physical properties of the amorphous aromatic random copolymer and the molding and evaluation of the polyester composition were performed in the following manner.

Softening point) The softening point of the amorphous aromatic random copolymer is determined by increasing the temperature at a rate of 5°C/min using a melting point measuring device manufactured by Yanagimoto Seisakusho, and measuring the temperature at which the copolymer softens. did.

Injection molding> The dried polyester composition was molded using an injection molding machine model 15-35P manufactured by Toshiba Machine ■ at a mold temperature of 70°C to a thickness of 0.2 cm, @1.27 cm, and a length of 6.35 cm.
A strip-shaped test piece was prepared.

Bending test〉 The above test piece was tested using an Instron tensile tester model 112.
2 at 23°C1 crosshead speed 5mm/m
The test was carried out under conditions of in.

(Crystallization speed) Thickness 0.2 cm, width 1.27 cut from injection molded sample
Cm% Using a rectangular test piece with a length of 2 cm, a DuPont Dynamic Mechanical Analyzer Model 981 was used.
The temperature dependence of the elastic modulus was measured using the mold.

Elastic modulus at 100°C (E, D) and elastic modulus at 30°C (
The ratio E too / E *o with El, ) was used as an index representing the crystallization rate.

Example 1 Distilled water 312mZ in a 500mf reactor equipped with a stirrer.

2.14g of polyacrylic acid, 68g of styrene as a dispersant
．． 0 g of methacrylic acid, 10.0 g of methacrylic acid, and 0.78 g of benzoyl peroxide were sequentially charged. After replacing the inside of the vessel with nitrogen gas by bubbling nitrogen for 15 minutes,
The temperature was raised to 80"C while stirring at 100 pm, and turbid polymerization was carried out for 6 hrQ.

The produced granular styrene/methacrylic acid resin was washed, made hydrophilic, and dried. The yield of the produced polymer was 73.8 g (94
, 6%). The number average molecular weight Mn measured by GPC (THF solvent, 40°C) is 33000 molecular weight distribution Mw
/in was 2.8. Further, the methacrylic acid content in the produced polymer determined by elemental analysis was 15 mo1%.

60 g of this styrene/methacrylic acid copolymer was placed in a 500 cm reactor equipped with a cooler, and 240 g of CHCl was added.
mj and MeOII60mZ were charged and the temperature was raised to 60°C.

After the polymer was dissolved, 10 mf of an aqueous solution containing 1.85 g of Na011 was added dropwise over 5 minutes and reacted for 4 hours.

The reaction solution was precipitated into hexane to recover the precipitated polymer. The yield of the produced polymer was 50 g. Table 1 shows the results of analyzing the produced polymer (sample 1). As a result of elemental analysis, it was found that 75% of the methacrylic acid component was neutralized and turned into Na salt.

Next, polyethylene terephthalate resin ([η) = 0
．． 60 dl/g) 100 parts, 1.5 parts of the sample synthesized by the above method using a 20 mm l extruder (L/D = 28, Dalmage type screw) at a resin temperature of 260°C.
, melt friending was carried out under the conditions of a screw rotation speed of 3 Orpm. The results of examining its physical properties are shown in Table 2.

Examples 2 to 16 Various styrenic hydrocarbon polymers (samples 2 to 14) shown in Table 1 were synthesized by the same method as in Example 1. These polymers and polyethylene terephthalate resin ([η) = 0.65 dl/g) were mixed according to the method of Example 1 to produce blend polymers having the compositions shown in Table 2. The results of measuring the physical properties are shown in Table 2.

Comparative Examples 1 to 7 Various styrenic hydrocarbon polymers (samples 15 to 18) shown in Table 1 were synthesized by the same method as in Example 1. These polymers and polyethylene terephthalate resin ([η] = 0.60 dl/g) were mixed according to the method of Example 1 to produce blend polymers having the compositions shown in Table 2. The results of measuring the physical properties are shown in Table 2.

Procedural amendment (method) July 1985 JO Commissioner of the Japan Patent Office Michibe Uga1, Indication of the case 1985 Patent Application No. 1215932, Name of the invention Amorphous aromatic random copolymer and Its use 3, relationship with the case of the person making the amendment Patent applicant (58B) Mitsui Petrochemical Industries Co., Ltd. Representative Shogo Takebayashi 4, Agent 3-2-5 Kasumigaseki, Chiyoda-ku, Tokyo 100, Order of amendment Date 8, Contents of the amendment (Application for correction attached) (ii. The title of "Patent application" is corrected to "Patent application (Patent application pursuant to the proviso to Article 38 of the Patent Act)".

(2) Add "2. Number of inventions stated in the claims: 2" before the "Inventor" column of the application.

that's all

Claims (2)

[Claims] (1) 50 to 99.8 mol% of the aromatic monomer component unit (a) consisting of styrene or its lower alkyl group substituted product, and 0.2 to 50 mol % of the (meth)acrylic acid component unit (b) %, a substantially linear amorphous material formed from 0.2 to 50 mol % of (meth)acrylate component units (c) and 0 to 40 mol % of alkyl (meth)acrylate component units (d) It is an aromatic random copolymer, and (i) gel permeation chromatography (GP
The number average molecular weight (@M@n) measured in C) is in the range of 2000 to 300000, the molecular weight distribution (@M@w/@M@n) is in the range of 1.2 to 15, and ( ii) When the content of the (meth)acrylic acid-synthesizing acrylate component unit (c) in the copolymer is X_2 mol%, X_1 and X_2 have the general formula y=X_2-0.3X_
An amorphous aromatic random copolymer characterized by satisfying the relationship 1≦16. (2) 50 to 99.8 mol% of the aromatic monomer component unit (a) consisting of styrene or its substituted product with a lower alkyl group, and 0.2 to 50% of the (meth)acrylic acid component unit (b) a substantially linear amorphous material formed from 0.2 to 50 mol% of (meth)acrylic acid component units (c) and 0 to 50 mol% of alkyl (meth)acrylate component units (d); It is an aromatic random copolymer, and (i) gel permeation chromatography (GP
The number average molecular weight (@M@n) measured in C) is in the range of 1000 to 300000, the molecular weight distribution (@M@w/@M@n) is in the range of 1.2 to 15, and ( ii) (meth)acrylic acid component unit in the copolymer (
When the content of b) is X mol% and the content of (meth)acrylate component unit (c) is X_2 mol%, X_
1 and X_2 satisfy the relationship of the general formula y=X_2-0.3X_1≦16. A compounding agent for polyester resin comprising an amorphous aromatic random copolymer represented by: