JPH03163153A - Multilayered polymer resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in transparency and stress whitening resistance by mixing a specified multilayered polymer with a thermoplastic resin. CONSTITUTION:99-1wt.% multilayered polymer prepared by graft-bonding 50-91wt.% innermost layer polymer comprising 100 pts.wt. total of 60-100 pts.wt. alkyl acrylate (a) having an 8C or lower alkyl group, 0-40 pts.wt. monomer (b) having a copolymerizable double bond and 0-10 pts.wt. polyfunctional monomer (c) and 0.1-5 pts.wt. graft-crosslinking agent and having a gel fraction >=60wt.% and a glass transition temperature <=0 deg.C with 10-49wt.% outermost layer polymer comprising 60-100 pts.wt. alkyl acrylate (d) having a 4 C or lower alkyl group and 0-40 pts.wt. component (b) and having a glass transition temperature >=60 deg.C is mixed with 1-99wt.% at least one thermoplastic resin selected from among a (co)polymer of a vinyl monomer and/or a vinylidene monomer of formulas I-III (wherein X and Y are each H, Cl, Br, F, CN3, COOH, COOCH3 or the like; Z is H, Cl, F or CF3; and R<2> is a fluoroalkyl group), a polycarbonate, a thermoplastic polyester and a polyamide.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilayer polymer resin composition, and more specifically, the present invention relates to a multilayer polymer resin composition, and more specifically, a multilayer polymer having excellent flexibility, transparency, and weather resistance is blended with a specific thermoplastic resin. The present invention relates to a multilayer structure polymer resin composition which has excellent transparency and has no or very little stress whitening property.

Generally, as a means to improve the impact resistance of thermoplastic resins, various attempts have been made to introduce so-called rubber components into the resins. The most common such method is to introduce diene rubber, but diene rubber has extremely poor weather resistance, so this method is inappropriate for applications that require weather resistance.

In order to impart impact resistance without reducing weather resistance, various methods of blending acrylic rubber polymers have been studied, and the problem of weather resistance has been solved to some extent; however, such blend systems Significant stress whitening occurs, greatly reducing its commercial value, and the transparency that can be obtained is typically subject to limitations.

For example, polymethyl methacrylate (hereinafter abbreviated as PMMA), which has an extremely beautiful appearance and excellent weather resistance, is strongly desired to have improved impact resistance and elasticity. Attempts to introduce a rubber component into PMMA by simply copolymerizing the components have been proposed in the past, but in both cases, the introduction of a rubber component greatly reduces weather resistance, transparency, etc., and the appearance is poor. No satisfactory results have been obtained.

Several methyl methacrylate-based multilayer polymers containing acrylic rubber have been proposed so far, especially from the viewpoint of molding materials for films and sheets, but these have sacrificed transparency, which is an inherent characteristic of methyl methacrylate-based resins. Moreover, stress whitening resistance, which is a common drawback of impact-resistant resins, has hardly been improved.

In order to obtain a thermoplastic resin composition with excellent transparency, weather resistance, impact resistance, and stress whitening resistance, it is necessary to use a crosslinked elastic layer and a resin layer mainly composed of alkyl acrylate, which have been proposed so far. At present, a satisfactory thermoplastic resin composition cannot be obtained even if a simple multilayer polymerization of the above is blended with other thermoplastic resins.

In view of the current situation, the present inventors have made extensive studies to obtain a thermoplastic resin composition having the above-mentioned characteristics.
By blending a specific thermoplastic resin in a specific range with a multilayer polymer with a specific structure that has excellent flexibility, transparency, and weather resistance, it has excellent transparency and no stress whitening. Alternatively, the inventors have discovered that a thermoplastic resin composition with a very small amount can be obtained, and have arrived at the present invention.

That is, the present invention is a multilayer structure polymer resin composition comprising 99 to 1% by weight of the following multilayer structure polymer [I] and 1 to 99% by weight of thermoplastic resin [1].

Multilayer structure polymer [■]: (AI R0~1nn Alkyl acrylate (A,) having an alkyl group under Raigoro's Kishigata Hatsu gIII. Monomer having a copolymerizable double bond of 0 to 40 parts by weight (A), 0-10 parts by weight of polyfunctional monomer (A3), and (A,
) to (A3) in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the polymer, the gel content is 60% by weight or more, and the glass transition temperature is 0°C or less,
Innermost layer polymer (A) whose proportion in the multilayer structure polymer is 51 to 90% by weight: and (B) 60 to 100 parts by weight of alkyl methacrylate having an alkyl group having 4 or less carbon atoms (Bll, and 0 Consisting of a polymer of ~40 parts by weight of a monomer (B) having a copolymerizable double bond, with a glass transition temperature of 60'C or higher, and a proportion of 10~40 parts by weight in the multilayer structure polymer. A multilayer structure polymer in which 49% by weight of the outermost layer (rB) is grafted.

Thermoplastic resin [■]: At least one polymer selected from the following groups (a) or (b), or at least one polymer selected from each of the groups (a) and (b). blend.

(a) The following formula: X / (at) CHz = C \ Y (wherein,
CHa, COOH, COOCH3, CN, OC
OCH3, COCHs, C. H. , S
Represents o3H and OR'. (a2) CF. =CFZ (wherein, Z represents H.Cβ, F or CF.) or (as) CH. =C-COOR2 CH. (In the formula, R2 represents a fluoroalkyl group) A homopolymer of vinyl monomer or vinylidene monomer or a copolymer of these monomers.

(b) Polycarbonates, thermoplastic polyesters and polyamides.

The present invention will be explained in more detail below.

The innermost layer polymer (A) constituting the multilayer structure polymer used in the present invention is a component for imparting flexibility to the polymer.

The alkyl acrylate (A,) having an alkyl group having 1 to 8 carbon atoms constituting the innermost layer polymer (A) is linear,
Any type of branched acrylate may be used, and methyl acrylate, ethyl acrylate, probyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, etc. are used alone or in combination, but the glass transition temperature (hereinafter referred to as Tg) (abbreviation) is more preferable. These alkyl acrylates (AI) are 6
It is used in a range of 0 to 100 parts by weight (hereinafter "parts by weight" is abbreviated as "parts").

Further, the monomer (A2) having a copolymerizable double bond is preferably an acrylic monomer other than the above, such as alkyl acrylate, lower alkoxy acrylate, cyanoethyl acrylate, acrylamide, acrylic acid, or methacrylic acid. -40 parts. Others (A
2) Styrene as a component within a range not exceeding 40% by weight;
Alkyl-substituted styrene, acrylonitrile, methacrylonitrile, etc. can be used.

Furthermore, the polyfunctional monomer (A3) is preferably an alkylene glyconyl dimethacrylate such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and brobylene glycol dimethacrylate. , divinylbenzene, trivinylbenzene, etc.
111. S Fumas III/ kmt. It is possible to use it. These monomers work effectively to crosslink the layer in which they are contained, but do not work on bonding between layers with other layers. These polyfunctional monomers (A,) are polymers (
In constructing A), if the condition of gel content of 60% by weight or more is satisfied by the polymerization conditions or the use of a grafting agent, it is not necessary to use 10
It may be used as long as it is within this range. When the polyfunctional monomer (A,) is used in an amount exceeding 10 parts, the flexibility of the polymer (A) decreases.

The grafting agent is an essential component for creating an effective chemical bond with the outermost resin layer or intermediate layer.
0.1 to total filoO parts of (A,) to (A,)
It is used in an amount of 5 parts, preferably 0.5 to 2 parts.

If the amount of graft cross-agent used is less than 0.1 part, the amount of effective graft bonding will be too small, and layer destruction will easily occur during molding, resulting in a significant decrease in transparency, etc. On the other hand, if more than 5 parts is used, the elasticity decreases. As the graft cross-agent, copolymerizable α,β-monounsaturated monocarboxylic acid or dicarboxylic acid allyl ester, meta-allyl ester,
Crotyl ester, triallyl cyanurate, triallyl isocyanurate, etc. are used, and allyl methacrylate and triallyl cyanurate are particularly preferred. In such a graft cross-agent, the conjugated unsaturated bond of the ester reacts much faster than the allyl group, methallyl group or crotyl group, and is chemically bonded. During this time, a substantial portion of the allyl group, methallyl group, or crotyl group effectively functions in the polymerization of the next layer polymer (B) and provides a graft bond between the two adjacent layers.

The innermost layer polymer (A) as described above needs to be an elastic body that has been crosslinked to some extent and has a Tg of 0°C or less, and has a gel content of 60% by weight or more, preferably 80% by weight, Particularly favorable results are obtained when the degree of swelling is between 5 and 30.

The amount of the polymer (A) in the acrylic multilayer structure polymer is 51 to 90% by weight. If the amount is less than 51% by weight, the desired excellent flexibility cannot be imparted to the acrylic multilayer structure polymer. On the other hand, if the amount exceeds 90% by weight, the entire polymer becomes rubbery and not only becomes difficult to handle, but also various physical properties such as weather resistance are significantly reduced. The innermost layer polymer (A) made of a crosslinked elastic body of acrylic rubber may have a two-stage structure or a three-stage structure, if necessary.

The outermost layer polymer (B
) is essentially a resin layer, which gives the polymer ease of handling as a resin and is also primarily responsible for various properties such as weather resistance. Therefore, T of the outermost layer polymer (B)
g needs to be 60°C or higher, preferably 8
The temperature is 0°C or higher.

As the alkyl methacrylate (B,) having an alkyl group having 4 or less carbon atoms forming the outermost layer polymer (B), at least one of methyl methacrylate, ethyl methacrylate, proyl methacrylate, butyl methacrylate, etc. is in the range of 60 to 100 parts. Methyl methacrylate is particularly preferred.

As the monomer (B3) having a copolymerizable double bond, in addition to an alkyl acrylate having an alkyl group having 8 or less carbon atoms, those shown in the above (Ax) d can be used in a range of 0 to 40 parts. It will be done. The amount of the outermost layer polymer (B) in the acrylic multilayer structure polymer is 10 to 49% by weight.

If the amount is less than 10%, a stable polymer cannot be obtained from the viewpoint of polymerization, coagulation operations, etc. Moreover, if the amount exceeds 49%, the content of the innermost layer polymer (A) becomes too small to obtain the desired flexibility.

Incidentally, during the polymerization of the outermost layer polymer (B), it is also possible to adjust the degree of polymerization using a chain transfer agent or the like, and this is often preferable.

The acrylic multilayer structure polymer used in the present invention has the innermost layer polymer (A) and outermost layer polymer (B) as basic structural units, and the proportion of the multilayer polymer in the multilayer polymer is 51 to 85%. 10 to 90 parts of alkyl methacrylate (C,) having an alkyl group of up to 4 carbon atoms, 10 to 90 parts of an alkyl group of up to 8 carbon atoms,
Alkyl methacrylate (C
．． ), 0 to 20 parts of a monomer (C3) having a copolymerizable double bond, 0 to 10 parts of a polyfunctional monomer (C4), and (C1) to
It is possible to arrange one or more intermediate layers consisting of a polymer of 0.1 to 5 parts of a graft cross-agent based on 100 parts of the total amount of (C4). Here, each component (C+) to (C4) and the kraft cross agent are the polymer (A) and the polymer (
The same components as those used in B) are used.

This intermediate layer is arranged to achieve more effective bonding between the innermost crosslinked elastic layer and the outermost resin layer, thereby further improving transparency and
The characteristics of the crosslinked elastic layer and resin layer, such as flexibility and weather resistance, are the best among all acrylic multilayer polymers! The appropriate amount of (C) is 5 to 30% by weight,
If it exceeds 30%, the overall balance of the polymer will be disturbed, which is not preferable.

Furthermore, each layer of the acrylic multilayer structure polymer used in the present invention must be organically bonded, and the outermost layer (
It is preferable that at least the amount of H in the total amount of B) and the intermediate N (C), or in the outermost layer (B) if there is no intermediate layer (C), is grafted to the innermost layer.

The gel content and degree of swelling of each layer of the polymer of the present invention are as follows:
This refers to the value measured as follows.

A predetermined amount of the polymer was collected in accordance with JIS K6388 and immersed in methyl ethyl carbonate (MEK) at 25° C. for 48 hours. After immersion, the swollen sample is pulled up, the adhered MEK is wiped off, and then its weight is measured. Then,
Dry M4 is removed from MEK in a vacuum dryer, and the absolute dry weight after constant weight is read.

MEK weight after swelling - absolute dry weight? The gel content of the entire multilayer polymer is determined by preparing a 1% by weight MEK solution of the polymer, leaving it at 25°C for a day and night, and then centrifuging it for 16,000 ml. p. m. It refers to the weight percent of insoluble matter after centrifugation for 90 minutes.

Furthermore, the glass transition temperature (Tg) referred to in the present invention is calculated from the commonly known FOX equation: l a I a 2 ■=■0 Tg Tg+ Tgz. In the formula, al and a2 each represent a weight fraction.

The multilayer structure polymer used in the present invention is usually obtained by a sequential multistage polymerization method using an emulsion polymerization method. Middle class (C
) in multiple layers, multi-stage polymerization may be carried out while gradually reducing the amount of alkyl acrylate (C.). When carrying out a sequential multi-stage polymerization method using emulsion polymerization method, a predetermined amount of an emulsifier, a catalyst, a monomer, etc. are added to an aqueous solvent and reacted, and after each reaction, the monomers and monomers forming the upper layer are added. By sequentially adding a polymerization initiator to the reaction system, the multilayer structure polymer used in the present invention can be obtained.

There are no particular restrictions on the emulsifier, catalyst, etc. used in the production of the multilayer structure polymer, and emulsifiers, catalysts, etc. used in ordinary emulsion polymerization can be used. Typical examples of emulsifiers include anionic surfactants such as long-chain fatty acid salts, sulfonic acid salts, ester salts of sulfosuccinic acid, phosphate ester salts, and acid amide type anionic surfactants. Representative examples of catalysts include inorganic peroxides such as potassium persulfate, organic peroxides such as cumene hydroperoxide and lauroyl peroxide, and azo initiators such as azobisisobutyronitrile. can be mentioned as cumene hydroperoxide dosodium formaldehyde sulfoxy.

The temperature conditions and polymerization time for polymerization of multilayer polymers depend on the catalyst used, etc., and any conditions are possible as long as the polymerization proceeds smoothly to the final stage, but usually is polymerized within the temperature range of 30-95°C, and the polymerization time is 3-20 hours. Note that it is often preferable to polymerize the crosslinked elastic body portion of the polymer at a relatively low temperature.

Furthermore, the method for producing the multilayer structure polymer used in the present invention is not particularly limited to the above method, and for example, an emulsion suspension polymerization method in which emulsion polymerization is then converted to suspension polymerization at the time of polymerization of the outermost layer polymer. It can also be obtained by

There is no particular restriction on the emulsion particle size in the final polymer of the multilayer structure polymer, but it is between 800 and 2.0
．． The most preferable range is about 00 people.

The latex of the multilayer polymer is subjected to a salting-out treatment if necessary, and then subjected to furnace filtration, water washing, dehydration, drying, etc., to form a powder-like polymer.

The above multilayer structure polymer has excellent transparency even when mixed with other compatible thermoplastic resins having different refractive indexes, and can be made into a resin composition with no stress whitening property or very little stress whitening property. . In particular, when blended with a methyl methacrylate resin, a resin composition with excellent transparency, stress whitening resistance, weather resistance, and impact resistance can be obtained.

It is surprising that stress whitening properties are extremely low even in polymer blend systems. This is based on the effect of the special structure of the multilayer polymer, and cannot be predicted from conventional methods of introducing rubber components.

To explain the polymer blend system in more detail,
For example, when mixed with vinyl chloride resin, polystyrene, AS resin, polycarbonate, etc., the multilayer structure polymer used in the present invention acts as a type of weather resistance/impact resistance modifier, and improves weather resistance/impact resistance. This results in a significant improvement in impact resistance.

In addition, blend compositions containing polyvinylidene fluoride have excellent properties such as weather resistance, transparency, stress whitening resistance, chemical resistance, toughness, and moldability. A resin composition comprising 50 to 99 parts of a multilayer structure polymer.

It is also an excellent material for film forming, and provides a transparent, tough film with excellent weather resistance, stress whitening resistance, chemical resistance, etc. By laminating the surface of an ordinary molded product, the overcast film can easily impart weather resistance and design effects, and has extremely high commercial value.

The present invention will be specifically explained below using Examples.

All parts in the examples are by weight.

In addition, the abbreviations in the examples are as follows.

MMA Methyl methacrylate BuA Butyl acrylate TAC }-Reallyl cyanurate CHP Cumene hydroperoxide SFS Sodium formaldehyde sulfoxylate Example 1 In a reaction vessel with a cooler, 250 parts of ion exchange water, 1.5 parts of sulfosuccinate Sorg salt, SFS 0 .0
After charging 5 parts of BuA and stirring under a nitrogen stream to sufficiently replace the inside of the container with nitrogen, add 70 parts of BuA and 0.35 parts of TAC.
A monomer mixture consisting of 0.1% CHP and BuA was charged. In addition, unless otherwise specified, all monomers added in each subsequent step shall contain 0.1% CHP for each monomer. Next, the temperature of the reaction vessel was raised to 50° C. while stirring at a rotational speed of 20 O rpm under a nitrogen stream, and polymerization was continued while stirring for 180 minutes to complete the polymerization of the innermost layer polymer (A). The resulting innermost layer polymer (A) had a particle size of about 0.1
3μ, Tg is -40℃, gel content is 89% by weight
, the degree of swelling is 19? It was.

Next, the temperature of the reaction system was raised to 80°C, and 0 was dissolved in a small amount of water.
．． After adding 0.05 parts of SFS, a monomer mixture consisting of 5 parts of MMA, 5 parts of BuA, and 0.05 parts of TAC was added dropwise to the reaction system over 30 minutes, and the mixture was maintained at 80°C with stirring for an additional 60 minutes. The intermediate layer (C) was polymerized. Next, 20 parts of MMA was added dropwise to the reaction system over 60 minutes, and the reaction system was maintained at that temperature for an additional 60 minutes to complete polymerization of the outermost layer polymer (B).

The obtained latex was salted out using 5 parts of CaCg, and after coagulating and solidifying, it was filtered, washed with water, and dried to obtain a dry powder. The obtained multilayer structure polymer had a Tg of 100° C. and a gel content of 85%.

80 parts of the multilayer structure polymer, 20 parts of polyvinylidene fluoride, and 1.5 parts of an ultraviolet absorber were mixed, extruded at 190° C. using an extruder with a screw having a diameter of 40 mm, and cut into pellets.

After sufficiently drying the obtained pellets, a 2 mm thick flat plate was molded using an injection molding machine and evaluated. The total light transmittance was 89%, the haze value was 2.7, the Shore D hardness was 35, and the flexural modulus was 1,600 kg/cm''.Also, in a 2,000 hour accelerated exposure test using a sunshine weather meter. It did not cause any discoloration or decrease in transparency, and had good weather resistance.Furthermore, using this pellet, a tube with an inner diameter of 6 mm and an outer diameter of 8 mm was molded, and it was transparent and sufficiently flexible.

Claims (1)

[Claims] 1. A multilayer structure polymer resin composition comprising 99 to 1% by weight of the following multilayer structure polymer [I] and 1 to 99% by weight of a thermoplastic resin [II]. Multilayer structure polymer [I]: (A) 60 to 100 parts by weight of alkyl acrylate (A_1) having an alkyl group having 8 or less carbon atoms, 0 to 40 parts by weight of a monomer having a copolymerizable double bond (A_2), 0 to 10 parts by weight of a polyfunctional monomer (A_3), and (A
0.1 per 100 parts by weight of the total amount of _1) to (A_3)
It consists of a polymer of ~5 parts by weight of a graft cross-agent, has a gel content of 60% by weight or more, a glass transition temperature of 0°C or less, and accounts for 51 to 90% by weight in the multilayer structure polymer. Innermost layer polymer (A); and (B) 60 to 100 parts by weight of alkyl methacrylate (B_1) having an alkyl group having 4 or less carbon atoms, and 0 to 40 parts by weight of a copolymerizable double bond. It consists of a polymer of monomer (B_2), has a glass transition temperature of 60°C or higher, and accounts for 10 to 49% by weight in the multilayer structure polymer.
A multilayer structure polymer comprising an outermost layer polymer (B) which is graft-bonded. Thermoplastic resin [II]: At least one polymer selected from the following groups (a) or (b), or a mixture of at least one polymer selected from each of the groups (a) and (b). (a) The following formula: (a_1) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X and Y are respectively H, Cl, Br, F, CH
_3, COOH, COOCH_3, CN, OCOCH_
3, COCH_3, C_8H_5, SO_3H and OR
Represents ^1. However, R^1 is a lower alkyl group) (a_2) CF_2=CFZ (In the formula, Z represents H, Cl, F, or CF_3) or (a_3) ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ (Formula A homopolymer of a vinyl monomer or a vinylidene monomer or a copolymer of these monomers (wherein R^2 represents a fluoroalkyl group). (b) Polycarbonates, thermoplastic polyesters and polyamides. 2. A multilayer structure polymer resin composition comprising 99 to 1% by weight of the following multilayer structure polymer [III] and 1 to 99% by weight of thermoplastic resin [II]. Multilayer structure polymer [III]: (A) 60 to 100 parts by weight of alkyl acrylate (A_1) having an alkyl group having 8 or less carbon atoms, 0 to 40 parts by weight of a monomer having a copolymerizable double bond (A_2), 0 to 10 parts by weight of a polyfunctional monomer (A_3), and (A
0.1 per 100 parts by weight of the total amount of _1) to (A_3)
It consists of a polymer of ~5 parts by weight of a graft cross-agent, has a gel content of 60% by weight or more, a glass transition temperature of 0°C or less, and accounts for 51 to 85% by weight in the multilayer structure polymer. Innermost layer polymer (A); (C) 10 to 90 parts by weight of alkyl methacrylate having an alkyl group having 4 or less carbon atoms (C_1)
, 10 to 90 parts by weight of an alkyl acrylate (C_2) having an alkyl group having 8 or less carbon atoms, 0 to 20 parts by weight of a monomer having a copolymerizable double bond (C_3), 0 to 10 parts by weight Polyfunctional monomer (C_4), and (C
0.1 per 100 parts by weight of the total amount of _1) to (C_4)
At least one intermediate layer (C) consisting of a polymer of ~5 parts by weight of a graft cross-agent and having a proportion of 5 to 30% by weight in the multilayer structure polymer; (B) 60 to 100 parts by weight of carbon atoms; It consists of a polymer of alkyl methacrylate (B_1) having 4 or less alkyl groups and 0 to 40 parts by weight of a monomer (B_2) having a copolymerizable double bond, and has a glass transition temperature of 60°C or higher. The proportion in the multilayer structure polymer is 10 to 44% by weight.
A multilayer structure polymer in which outermost layer polymer (B) is successively graft-bonded. Thermoplastic resin [II]: At least one polymer selected from the following groups (a) or (b), or a mixture of at least one polymer selected from each of the groups (a) and (b). (a) The following formula: (a_1) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X and Y are respectively H, Cl, Br, F, CH
_3, COOH, COOCH_3, CN, OCOCH_
3, COCH_3, C_6H_5, SO_3H and OR
Represents ^1. However, R^1 is a lower alkyl group) (a_2) CF_2=CFZ (In the formula, Z represents H, Cl, F, or CF_3) or (a_3) ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ (Formula A homopolymer of a vinyl monomer or a vinylidene monomer or a copolymer of these monomers (wherein R^2 represents a fluoroalkyl group). (b) Polycarbonates, thermoplastic polyesters and polyamides.