JPH07196870A - Polymer blend containing monovinyl arene/ conjugated diene block copolymer - Google Patents

Abstract

PURPOSE: To obtain a polymer blend having a combination of transparency, rigidity, and toughness by blending a monovinyl arene/conjugated diene block copolymer with a modified poly(ethylene terephthalate) and a specified styrene polymer.

CONSTITUTION: A monovinyl arene/conjugated diene block copolymer (A) comprising about 55 to 95 wt.% monovinyl arene and about 45 to 5 wt.% conjugated diene is blended with a modified poly(ethylene terephthalate) (B) having been modified with a modifier being a diol, a diacid, a hydroxy acid or a mixture of at least two of them and about 5 to about 90 wt.%, based on the total weight of the polymer blend, styrene polymer (C) being a styrene/acrylonitrile copolymer, a styrene/methyl methacrylate copolymer, or a mixture thereof. The amount of the modified poly(ethylene phthalate) blended is desirably in the range of about 5 to 20 wt.%.

COPYRIGHT: (C)1995,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to blends containing monovinylarene / conjugated diene block copolymers and modified poly (ethylene terephthalate).

[0002]

BACKGROUND OF THE INVENTION Monovinylarene / conjugated diene copolymers are known and useful for a variety of purposes. Among those of particular interest are polymers capable of forming colorless, transparent articles having good physical properties. Such articles are useful in packaging such as toys, window components, beverage containers and blister packs.

[0003]

Accordingly, it would be desirable to develop a polymer blend having a combination of good transparency, stiffness, rigidity and toughness.

[0004]

The present invention provides a polymer blend having a combination of good clarity, stiffness and toughness. The present invention further provides a method of making a polymer having good transparency and good mechanical properties.

According to the present invention, (A) monovinylarene / conjugated diene block copolymer, (B) modified poly (ethylene terephthalate) and (C) styrene / acrylonitrile copolymer, styrene / methyl methacrylate copolymer. And a blend of styrenic polymers selected from the group consisting of mixtures thereof. In one aspect of the invention, the blend consists essentially of (A), (B) and (C). By the use of the term "consisting essentially of" it is intended that the blend be free of ingredients that substantially affect the desired properties imparted by the ingredients listed before the expression.

The present invention also relates to methods of making the blends and articles made therefrom. The polymers used in the present invention can be made by any means known in the art. Many suitable polymers are commercially available.

Component (A) monovinylarene / conjugated diene block copolymers useful in the present invention are ASTM
D-1238, 0.1 g / measured according to condition G
Melt flow greater than 10 minutes, preferably about 0.1g
Block copolymer having a melt flow in the range of / 10 min to about 100 g / 10 min. Preferably, the monovinylarene / conjugated diene block copolymer is AST
It will have a notched Izod impact strength of greater than 0.3 foot pounds per inch as measured according to MD-256.

Generally, the monovinylarene / conjugated diene block copolymer is in the range of about 55 weight percent to about 95 weight percent, preferably about 60 weight percent to about 95 weight percent, based on the total weight of the final block copolymer. And more preferably will contain the monovinylarene monomer in an amount ranging from 65 weight percent to 90 weight percent. Generally, the conjugated diene monomer will range from about 45 weight percent to about 5 weight percent, based on the total weight of the final block copolymer,
Preferably in the range of about 40 weight percent to about 5 weight percent and more preferably 35 weight percent to 1.
It will be present in the final block copolymer in an amount in the range of 0 weight percent.

The basic starting materials and polymerization conditions for making monovinylarene / conjugated diene block copolymers are described in US Pat. Nos. 4,091,053 and 4,58.
No. 4,346, No. 4,704,434, No. 4,7
04,435 and 5,227,419.

In a typical method of making these publications, the conjugated diene monomer and the monovinylarene monomer are continuously copolymerized in the presence of an initiator. Optionally, a mixture of monovinylarene monomer / conjugated diene monomer can be polymerized to form a monovinylarene / conjugated diene block. The initiator can be any organic monoalkali metal compound known for such purposes. Preferably, the initiator is provided in at least 3 batches. Small amounts of polar organic compounds, such as ethers, thioethers, and tertiary amines, can be used to improve the effectiveness of the initiator and in the mixed monomer charge of monovinylarene monomer. It can be used in a hydrocarbon diluent to randomize at least a portion. The polymerization method is about -100 ° C to about 1
It is carried out in a hydrocarbon diluent at any suitable temperature in the range of 50 ° C. and at a pressure sufficient to maintain the reaction mixture substantially in the liquid phase. Before charging the next charge, each monomer charge or monomer mixture charge under solution polymerization conditions such that the polymerization of each monomer charge or monomer mixture is substantially completed. Are polymerized.

Suitable conjugated dienes that can be used in the copolymer include conjugated dienes having 4 to 12 carbon atoms per molecule, with conjugated dienes having 4 to 8 carbon atoms being preferred. . Examples of such suitable compounds are 1,3-butadiene, 2-methyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2,3-
Includes dimethyl-1,3-butadiene, 1,3-pentadiene, 3-butyl-1,3-octadiene and mixtures thereof. Preferred dienes are 1,3-butadiene and isoprene, most preferably 1,3-butadiene.

Suitable monovinylarene compounds which can be used in the copolymer are 8 to 1 per molecule.
Monovinylarene compounds having 8 carbon atoms, preferably 8 to 12 carbon atoms. Examples of such suitable compounds are styrene, alpha-methylstyrene,
2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene,
4-ethylstyrene, 4-n-propylstyrene, 4-
t-butyl styrene, 2,4-dimethyl styrene, 4-
Cyclohexyl styrene, 4-decyl styrene, 2-ethyl-4-benzyl styrene, 4- (4-phenyl-n)
-Butyl) styrene, 1-vinylnaphthalene, 2-vinylnaphthalene and mixtures thereof. Styrene is the preferred monovinylarene compound.

The modified poly (ethylene terephthalate) of component (B) is a high molecular weight polymer made by condensing ethylene glycol with terephthalic acid or dimethyl terephthalate and a comonomer or modifier. How to build is not important. Poly (ethylene terephthalate) is modified by including a comonomer or modifier selected from the group consisting of diols, diacids, hydroxyacids and mixtures thereof. Generally, the comonomer or modifier is present in an amount ranging from about 5% to about 20% by weight based on the total weight of modified poly (ethylene terephthalate). Such comonomers or modifiers include 1,4-butanediol, 1,4-cyclohexanedimethanol,
Diethylene glycol, hydrogenated polyalkylene oxides, neopentyl glycol, butylene glycol,
It includes various diols such as 1,3-propanediol and mixtures thereof. Similarly, such comonomers or modifiers include isophthalic acid, adipic acid, sebacic acid,
Various diacids such as 2,6-naphthalenedicarboxylic acid, p
-Hydroxy acids such as hydroxybenzoic acid and mixtures thereof can be included. Mixtures of modified poly (ethylene terephthalate) can be used. Suitable modified poly (ethylene terephthalate) is commercially available. Of the suitable modifiers, diols are preferred. At least 50 mol% ethylene glycol and 20 to 5 modifier
Modified poly (ethylene terephthalate) containing 0 mol% 1,4-cyclohexanedimethanol is particularly preferred. The modified poly (ethylene terephthalate) used herein generally has an inherent viscosity of at least about 0.2, preferably in the range of about 0.2 to about 10.0, as measured by ASTM D-2857. Have. Inherent viscosity is measured in methylene chloride and trifluoroacetic acid in a volume ratio of 3: 1 at 30 ° C.
Preferably, the modified poly (ethylene terephthalate) has a refractive index similar to that of the monovinylarene / conjugated diene used, ie, ASTM 5
42, and is in the range of about 1.56 to about 1.58.

Component (C) is a styrenic polymer selected from the group consisting of styrene / methyl methacrylate copolymers, styrene / acrylonitrile copolymers and mixtures thereof.

Styrene / acrylonitrile (SAN)
Acrylonitrile, a styrenic monomer that is well known in the art and can be various derivatives of styrene, either styrene alone or substituted on either or both of the benzene ring and vinyl groups, and acrylonitrile, It is a copolymer with an ethylenically unsaturated nitrile monomer including methacrylonitrile and ethacrylonitrile.

The composition of the styrene / acrylonitrile copolymer can vary widely. Generally, acrylonitrile will be present in an amount in the range of 5 weight percent to 50 weight percent, preferably in the range of 5 weight percent to 40 weight percent, based on the weight of the styrene / acrylonitrile copolymer. Generally, the styrenic monomer will be present in the range of 95 weight percent to about 50 weight percent, preferably in the range of 95 weight percent to 60 weight percent, based on the weight of the styrene / acrylonitrile copolymer. The styrene / acrylonitrile copolymer is generally from about 0.2 g / 10 min to about 100 g / 10, measured according to ASTM 1238.
It has a melt flow rate in the range of minutes. Preferably,
A styrene / acrylonitrile copolymer is selected that exhibits a refractive index similar to the monovinylarene / conjugated diene copolymer used, that is, a refractive index in the range of about 1.56 to about 1.58 as measured according to ASTM 542.

The styrene / methyl methacrylate copolymer (SMMA) can be made by any method known in the art. Typically styrene / methylmethacrylate copolymers are made by copolymerization of styrene and methylmethacrylic acid monomers using free radical initiators such as peroxy or azo catalysts.

The composition of the styrene / methyl methacrylate copolymer can be widely varied. Generally, methyl methacrylate will be present in an amount ranging from about 5 to about 50 weight percent based on the weight of the styrene / methyl methacrylate copolymer. Styrene / methyl methacrylate copolymers are generally measured according to ASTM 1238,
It has a melt flow rate in the range of about 0.2 g / 10 min to about 100 g / 10 min. Preferably, a refractive index similar to the monovinylarene / conjugated diene copolymer used,
That is, about 1.56 ~ measured according to ASTM 542.
A styrene / methyl methacrylate copolymer having a refractive index in the range of about 1.58 is selected.

The composition of the polymer blend can vary widely. Generally, component (A) monovinylarene /
The conjugated diene block copolymer is from about 5 weight percent to about 90 weight percent, preferably from about 10 weight percent to about 80 weight percent, more preferably from 10 weight percent to, based on the total weight of the polymer blend.
Present in an amount in the range of 65 weight percent.

The modified poly (ethylene terephthalate) of component (B) is generally from about 5 weight percent to about 90 weight percent, preferably from about 10 weight percent to about 80 weight percent, and more preferably based on the total weight of the polymer blend. Is present in an amount ranging from 10 weight percent to 65 weight percent.

Generally, component (C) is from about 5 weight percent to about 90 weight percent, preferably from about 10 weight percent to about 8 weight percent, based on the total weight of the polymer blend.
It is present in an amount in the range of 0 weight percent, more preferably 10 weight percent to 65 weight percent.

The polymer blends exhibit the desired combination of properties. The polymer blend has a haze of less than about 15 percent as measured by a Gardner Hazemeter according to ASTM 1003 using 5 mil thick specimens.
e), preferably exhibiting a haze of less than about 10 percent. The polymer blend exhibits a Shore D hardness of greater than about 70, measured according to ASTM D-2240. Generally, the flexural modulus of the polymer blends, measured according to ASTM D-648, is greater than about 200 kilopounds per square inch (ksi). The polymer blend exhibits a notched Izod impact strength greater than 0.5 foot pounds / inch.

Blend mixing can be done by any method known in the art. Preferably,
The polymer is melt blended using any desired means such as a Banbury mixer, hot rolls or extruder. More preferably, the polymers are melt blended using extruder blending techniques. Single or twin screw extruders can be used. The polymer is dry blended prior to melt blending.

Blend mixing conditions will depend on the blend mixing technique and polymer used. If the initial dry blending of the polymer is used, the mixing conditions are from room temperature to just below the melting temperature of the polymer, and in the range of a few seconds to several hours, for example 2 seconds. ~ 30
Blend mixing times in the range of minutes may be included.

During melt blending, the temperatures at which the polymers are combined in the mixer are generally the highest melting point of the polymers used and up to about 100 ° C. above such melting point.
Would be in the range between.

The time required for melt blending can vary widely and depends on the blend mixing method used. The time required is sufficient to thoroughly mix the ingredients. Generally, each polymer is blended for a period of about 10 seconds to about 15 minutes.

The polymer blends include stabilizers, antioxidants,
Anti-blocking agent
agents), mold release agents, dyes, pigments, additives such as flame retardants, and reinforcing agents such as fillers and glass fibers, as long as their amount and type do not interfere with the purpose of the invention. . Polymer blends made in accordance with the present invention are useful in making articles that can be made by milling, extrusion or injection molding. The following examples are provided to further illustrate the present invention and are not intended to limit its scope thereby.

[0028] EXAMPLES The following example illustrates the combination of transparency and mechanical properties of various polymer blends. From the group of styrene / butadiene block copolymer (SB), modified poly (ethylene terephthalate) (PETG), and styrene / acrylonitrile (SAN), styrene / methyl methacrylate copolymer (SMMA) and mixtures of SAN and SMMA. The selected third component is Warener & Pflei
Blend blended using a derer ZSK-30 twin screw extruder.

Continuous solution polymerization according to the method described in US Pat. No. 4,584,346.
al solution polymerizatio
A styrene / butadiene block copolymer (SB) was prepared using n) and three charges of initiator. The polymerization reaction was continued until the completion after charging each monomer. The order of charging styrene (S), butadiene (B), initiator (i) and coupling agent (ca) was as follows: S, i, i, S, B, i, S, B, ca. Polymerization temperatures ranged from about 38 ° C. to about 110 ° C. and pressures ranged from about 2 psig to about 60 psig. The weight ratio of styrene to butadiene in the styrene / butadiene block copolymer designated KR03 in Table 1 is 75 /
It was 25. The styrene / butadiene weight ratio in the styrene / butadiene copolymer designated KK38 in Table 1 was 70/30. After the completion of continuous polymerization, Viko
flex 71710 (Viking Chemica
l Co. A commercially available coupling agent containing epoxidized soybean oil) was charged into the reactor. The styrene / butadiene block copolymer was stabilized with Irganox 1076 and tris (nonylphenyl) phosphate. Styrene / butadiene block copolymer is ASTM D-123
8, measured according to condition G 5g / 10min-15g /
It showed a melt flow in the range of 10 minutes. The styrene / butadiene block copolymer exhibited a notched Izod impact strength of greater than 0.3 foot pounds / inch as measured according to ASTM D-256. KR03 is AS
It exhibited a refractive index of 1.571 as measured according to TM 542.

The modified poly (ethylene terephthalate) (PETG) used was Eastman Chemica.
was an ethylene-1,4-cyclohexylene dimethylene terephthalate copolymer Kodar 6763 from 1. PETG is measured according to ASTM 542,
It had a refractive index of 1.567, a notched Izod impact strength of 1.7 foot pounds per inch measured according to ASTM D-256 and a haze of 0.5 measured according to ASTM 1003.

The styrene / acrylonitrile copolymer (SAN) used was Lustran from Monsanto.
31 and contained 23% acrylonitrile. SAN is measured according to ASTM 542 to 1.
Refractive index of 57, notched Izod impact strength of 0.45 foot pounds per inch and 1.4% haze (ha
ze).

The styrene / methyl methacrylate copolymer (SMMA) used was Novacor Polym.
NAS 21 from ers. The SMMA copolymer exhibited a notched Izod impact strength of 0.36 foot pounds per inch and a refractive index of 1.57 measured according to ASTM 542.

Styrene / maleic anhydride copolymer (SMA) Dylark 332, commercially available from ARCO, is
Used for comparison as shown in the table. SMA
The copolymer exhibited a notched Izod impact strength of 0.2 foot pounds per inch and a refractive index of 1.581 measured according to ASTM 542.

Novacor Plastic Div
Polystyrene (PS) commercially available from Ision, Poly
stylene 555 was used for comparison as shown in Table 1. The PS polymer is 0.3
Notched Izod impact strength of 5 foot pounds per inch and measured according to ASTM 542, 1.
It has a refractive index of 59. The polystyrene melt flow rate was about 16 g / 10 min as measured according to ASTM 1238.

The results are summarized in Table 1. In the following table: Percent haze is ASTM 10
03. Hardness (Shore D) is ASTM
Measured according to D-2240. Flexural modulus in ksi was measured according to ASTM D-648.
Notched Izod impact strength in foot pounds / inch was measured according to ASTM D-256.

[0036]

[Table 1]

Table 1 shows experiments 105-112 of polymer blends using SB copolymer, PETG and SAN or SMMA or a mixture of SAN and SMMA.
Show that it produces a composition having a combination of good transparency and good mechanical properties as compared to experiments 103-104 of polymer blends containing SMA or PS.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C08L 67/02 LNZ

Claims (22)

[Claims] 1. The (A) monovinylarene is present in an amount in the range of about 55 weight percent to about 95 weight percent based on the weight of the monovinylarene / conjugated diene block copolymer and the conjugated diene is monovinylarene /
A monovinylarene / conjugated diene block copolymer present in an amount in the range of about 45 weight percent to about 5 weight percent based on the weight of the conjugated diene block copolymer, the monovinylarene / conjugated diene block copolymer being present based on the total weight of the polymer blend. A monovinylarene / conjugated diene block copolymer present in an amount ranging from 5 weight percent to about 90 weight percent, (B) a diol, a diacid, a hydroxy acid or two thereof.
A modified poly (ethylene terephthalate) modified with a modifier that is a mixture of one or more of about 5 weight percent based on the total weight of the polymer blend.
A modified poly (ethylene terephthalate) present in an amount in the range of about 90 weight percent, and (C) a styrene-based polymer which is a styrene / acrylonitrile copolymer, a styrene / methyl methacrylate copolymer or a mixture thereof. A styrenic polymer present in an amount ranging from about 5 weight percent to about 90 weight percent, based on the total weight of the polymer blend. 2. The modifier is from about 5 weight percent to about 2 based on the total weight of modified poly (ethylene terephthalate).
The blend of claim 1 present in an amount in the range of 0 weight percent. 3. The method of claim 1 or 2 wherein each of (A), (B) and (C) is present in an amount ranging from about 10 weight percent to about 80 weight percent based on the total weight of the polymer blend. Blend as described. 4. The blend of claim 3, wherein each of (A), (B) and (C) is present in an amount ranging from 10 weight percent to 65 weight percent based on the total weight of the polymer blend. 5. The blend according to claim 1, wherein the monovinylarene in the monovinylarene / conjugated diene block copolymer is styrene. 6. The blend according to claim 1, wherein the conjugated diene in the monovinylarene / conjugated diene block copolymer is butadiene. 7. The blend according to claim 1, wherein the modifier in (B) is a diol. 8. The blend according to claim 7, wherein the modifier comprises 1,4-cyclohexanedimethanol. 9. The styrene / acrylonitrile copolymer contains acrylonitrile in an amount ranging from about 5 weight percent to about 50 weight percent based on the weight of the styrene / acrylonitrile copolymer and from about 95 weight percent to about 50 weight percent. A blend according to any one of claims 1 to 8 containing styrene in an amount in the range of 50 weight percent. 10. The styrene / methyl methacrylate copolymer comprises methyl methacrylate in an amount ranging from about 5 weight percent to about 50 weight percent, based on the weight of the styrene / methyl methacrylate copolymer. 10. The blend of any one of claims 1-9, which contains styrene in an amount ranging from about 95 weight percent to about 50 weight percent. 11. The monovinylarene / conjugated diene copolymer is measured according to ASTM 542 and has a viscosity of about 1.
11. The blend according to any one of claims 1-10 exhibiting a refractive index of 56 to about 1.58. 12. The modified poly (ethylene terephthalate) is about 1. as measured according to ASTM 542.
A blend according to any one of claims 1 to 11 which exhibits a refractive index of 56 to about 1.58. 13. The styrene / acrylonitrile copolymer is measured according to ASTM 542 and has a viscosity of about 1.
13. The blend of any one of claims 1-12 exhibiting a refractive index of 56 to about 1.58. 14. The styrene / methyl methacrylate copolymer has a viscosity of about 1. measured according to ASTM 542.
14. A blend according to any one of claims 1-13 exhibiting a refractive index of 56 to about 1.58. 15. The notched Izod impact strength of the monovinylarene / conjugated diene copolymer measured according to ASTM D-256 of about 0.3 foot pounds per inch or greater. The blend of any one of claims. 16. Using a 50 mil thick specimen, A
16. The blend of any one of claims 1-15, which exhibits a haze of about 15 percent or less, as measured using a Gardner Hazemeter according to STM 1003. 17. The blend of claim 16, which exhibits a haze of 10 percent or less. 18. A blend according to any one of claims 1 to 17 which exhibits a Shore D hardness of 70 or greater as measured according to ASTM D-2240. 19. The blend of any one of claims 1-18 which exhibits a flexural modulus of about 200 kilopounds per square inch or greater, measured according to ASTM D-648. 20. A notched Izod impact strength of about 0.5 foot pounds per inch or greater, as measured according to ASTM D-256.
9. The blend of any one of 9 above. 21. A blend according to any one of claims 1 to 20 consisting essentially of (A), (B) and (C). 22. A blend according to any one of claims 1 to 21 made by melt blending (A), (B) and (C).