JPH0337255A - Lubricant for thermoplastic resin and thermoplastic resin composition containing the same - Google Patents

Abstract

PURPOSE:To prepare a lubricant which, when compounded into a thermoplastic resin compsn., imparts excellent flowability and releasability to a compsn. and gives a molded article of the compsn. an excellent gloss by using as the lubricant a two-step polymer obtd. by (co)polymerizing methyl methacrylate alone or a mixture thereof with another monomer in the presence of a specific copolymer under specific conditions. CONSTITUTION:10-70 pts.wt. methyl methacrylate alone or a mixture of 50wt.% or more methyl methacrylate with 50wt.% or less another monomer copolymerizable therewith is (co)polymerized in the presence of 30-90 pts.wt. copolymer which has a reduced viscosity (measured on a solution of 1g of the copolymer in 100ml of chloroform, at 25 deg.C) at 1.0dl/g or lower and is obtd, by copolymerizing 20-80wt.% acrylic ester (e.g. butyl acrylate) with 80-20wt.% arom. vinyl monomer (e.g. styrene), to give a two-step (co)polymer under the conditions under which when methyl methacrylate alone or the mixture is (co) polymerized in the absence of the copolymer the reduced viscosity of the resulting two-step (co)polymer of 1.5dl/g or lower is obtd. The two-step (co)polymer is used as a lubricant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lubricant for thermoplastic resins and a thermoplastic resin composition containing the lubricant.

The thermoplastic resin lubricant of the present invention can be used for vinyl chloride resin, polycarbonate resin, polyester resin, ABS resin,
Compositions blended with thermoplastic resins such as styrene resins, methacrylic resins, polyethylene resins, etc. exhibit excellent fluidity and mold releasability, especially when molded, while retaining the inherent properties of thermoplastic resins. The molded product has good gloss and transparency, and is also characterized by low heat colorability.

[Conventional technology]

Thermoplastic resins, particularly vinyl chloride resins, are widely used in various fields because of their excellent physical and chemical properties. However, vinyl chloride resin has the disadvantage of poor processability in various ways, and a solution to this problem is to add plasticizers, processing aids such as copolymers containing methyl methacrylate as a main component, and lubricants. Although this has been done, it was not possible to solve the problem by fishing by boat.

In order to solve these problems, Japanese Patent Publication No. 52-781 discloses a three-stage polymer consisting of a methyl methacrylate polymer component/styrene/(meth)acrylate copolymer component/methyl methacrylate polymer component; Japanese Patent Publication No. 52-3668 describes methyl methacrylate polymer J component/styrene/(meth)acrylic ester/
A two-stage polymer consisting of a polymer component of a polyfunctional monomer, and in Japanese Patent Publication No. 50-37699, an acrylic ester polymer component/(meth)acrylic ester, styrene or substituted styrene polymer component. It has been proposed to blend two-stage polymers consisting of the following into vinyl chloride resins and other thermoplastic resins as processing aids or plasticizers.

[Problems to be Solved by the Invention] The processing aids or lubricants proposed above improve the maintenance of transparency of vinyl chloride resin, processability such as drawdown, fluidity during molding, elongation at high temperatures, The aim is to improve the long-term sustainability of lubricity, such as release properties from the roll surface during calendering, and some results have been achieved. However, from the standpoint of improving productivity, improving quality, and saving energy, vinyl chloride resin has good fluidity during molding, the resin pressure required for molding is low, the lubricity is long-lasting, and molded products. There is a demand for lubricants with good gloss and transparency.
The processing aids or lubricants proposed above have not responded satisfactorily to this. Furthermore, depending on the molding processing conditions, an increase in deposits on the mold etc. (plate-out) may be observed, and it cannot be said that market demands are fully satisfied.

[Means to solve the problem]

The purpose of the present invention is to solve the above problems, namely:
Since the resin pressure can be lowered during molding, fluidity and lubricity are long-lasting, and mold releasability is excellent, and the molded product has good gloss and transparency, and is characterized by little heat discoloration. The present invention provides a thermoplastic resin composition.

The present invention is characterized in that (A) the reduced viscosity ηs p/c obtained by copolymerizing a monomer mixture consisting of 20 to 80% by weight of an acrylic acid ester and 80 to 20% by weight of an aromatic vinyl monomer is 1. Od
In the presence of 30 to 90 parts by weight of a copolymer of 1/g or less, (
B) 10 to 70 parts by weight of methyl methacrylate alone or a monomer mixture consisting of 50% by weight or more of methyl methacrylate and 50% by weight or less of another copolymerizable monomer,
When the methyl methacrylate or the monomer mixture is polymerized alone, the reduced viscosity ηsp/c of the (co)polymer is 1
．． 2 obtained by (co)polymerization so that it is 5a/g or less
A lubricant for thermoplastic resin comprising a step polymer is provided.

The present invention also provides a thermoplastic resin composition comprising 100 parts by weight of a thermoplastic resin and 0.05 to 10 parts by weight of the above lubricant for thermoplastic resins.

Examples of thermoplastic resins to which the thermoplastic resin lubricant of the present invention is blended include vinyl chloride resins, polycarbonate resins, polyolefin resins, polyester resins, vinyl fluoride resins, acrylonitrile-styrene copolymer resins, and methacrylic acid resins. , ABS resin, etc. Among these resins, vinyl chloride resin
Examples of ζ include polyvinyl chloride and a copolymer containing 70% by weight or more of units based on vinyl chloride. As monomers copolymerizable with vinyl chloride, monoethylenically unsaturated monomers such as ethylene, 1-propylene, vinyl bromide, vinylidene chloride, vinyl acetate, acrylic esters, and methacrylic esters can be used. .

The lubricant for thermoplastic resins of the present invention is a two-stage polymer obtained by sequentially polymerizing the monomer component (A) and the monomer component (B). This two-stage polymer mainly contains methyl methacrylate, which has the function of improving dispersibility and kneading with the vinyl chloride resin, on the outside of component (A), which has the function of imparting lubricity. (B) consisting of a co)polymer
) is a two-stage structure polymer containing components.

Component (A) is a copolymer consisting of 20-80% by weight of acrylic ester and 80-20% by weight of aromatic vinyl monomer, and the amount of acrylic ester used exceeds 80% by weight (aromatic vinyl monomer). If the amount is less than 20% by weight), the refractive index differs by 111 from that of vinyl chloride resin, resulting in poor transparency of the final product. Furthermore, when the amount of acrylic ester used is less than 20% by weight (the amount of aromatic vinyl monomer exceeds 80% by weight), the slipperiness is extremely reduced. The amount of acrylic acid ester used is preferably 30% to 80% by weight, and the amount of aromatic vinyl monomer used is preferably 70% to 20% by weight.

Component (A) is a copolymer with a reduced viscosity of 77 Sp/C of 1.0 d1/g or less. Specifically, a copolymer having such ηsp/c can be obtained by polymerization by adjusting the amount of a chain transfer agent such as normal octyl mercaptan, a catalyst, and the polymerization temperature. If ηs p/c exceeds 1.0a/g, the effect as a processing aid is recognized; for example, in extrusion molding, the resin thickens during molding, heat coloring occurs, and the effect as a lubricant is halved. Therefore, it is not desirable.

As the acrylic ester used for component (A),
Examples include ethyl acrylate, butyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, and the like. In order to impart a particularly good lubricity effect to the composition of the present invention, it is desirable that the acrylic ester used as (A) 1 minute is a monomer that provides a polymer with a low glass transition temperature. The use of an aromatic vinyl monomer, particularly styrene, as component A) is a necessary requirement for obtaining a resin with excellent transparency.

Styrene is preferred as the aromatic vinyl monomer, and ill styrene such as α-methylstyrene can also be used.

The blending ratio of component (A) is in the range of 30 to 90 parts by weight, preferably 35 to 80 parts by weight, based on 100 parts by weight of the total amount of surrounding components (A) and (B). If the blending ratio of component (A) is less than 30 parts by weight, the lubricity of the resin composition will be impaired;
If it exceeds 90 parts by weight, surface properties, transparency, and gloss will be impaired.

(B) Jiii is methyl methacrylate alone or a monomer mixture consisting of 50% by weight or more of methyl methacrylate and 50% by weight or less of other copolymerizable monomers
co)polymer. The proportion of methyl methacrylate in component (B) is 50m from the viewpoint of compatibility with vinyl chloride resin.
1% or more. There are no particular limitations on the monomer copolymerized with methyl methacrylate, and any appropriate monomer may be used depending on the final purpose. Examples of monomers to be copolymerized include unsaturated nitriles, vinyl esters, acrylic esters, and methacrylic esters other than methyl methacrylate. These may be used alone or in a mixed system of two or more. If the amount of this monomer used exceeds 50% by weight, the mutual effect of the acrylic ester of component (A) and the low molecular weight styrene polymer, such as the persistence of lubricity, will be extremely reduced. .

The blending ratio of component (B) is in the range of 10 to 70 parts by weight, preferably 10 to 60 parts by weight, based on 100 parts by weight of the total amount of surrounding components (A) and (B). If this blending ratio is less than 10 parts by weight, the polymer tends to cause secondary aggregation during dehydration and drying steps, which poses a problem in terms of productivity. on the other hand,
If the blending amount exceeds 70 parts by weight, the long-term sustainability of slipperiness will be lost.

The molecular weight of component (B) is such that the reduced viscosity η sp/c of the (co)polymer when the monomer and monomer mixture of component (B) are polymerized alone is 1.5 a/g or less. do. Lowering the molecular weight in this manner is a necessary condition for exhibiting sufficient effects as a lubricant. (B) vsp to component 1
If there is a portion where /c exceeds 1.5 dl/g, the resin will thicken during extrusion molding and its effectiveness as a lubricant will be halved. The reduced viscosity ηsp/c is the chain transfer agent,
It can be adjusted by the catalyst and polymerization temperature.

The two-stage polymer constituting the lubricant of the present invention can be easily obtained by sequentially polymerizing both the polymer components (A) and (B). Examples of polymerization methods include emulsion polymerization,
Examples include suspension polymerization and bulk polymerization, and among these, emulsion polymerization is preferred. In order to form a two-layer structure in production by the emulsion polymerization method, polymerization is proceeded without newly adding an emulsifier during the second stage polymerization, and it is possible to substantially form a homopolymer of component (B). This is desirable. The emulsifier may be any known emulsifier; for example, common anionic, cationic or nonionic surfactants can be used.

Depending on the type of emulsifier used, when the PL+ of the polymerization system becomes alkaline, an appropriate PL+ regulator may be used to prevent hydrolysis of the acrylic acid alkyl ester. pHA11 moderators include boric acid-potassium chloride-sodium hydroxide, potassium dihydrogen phosphate-disodium hydrogen phosphate, boric acid-potassium chloride-sodium carbonate, boric acid-sodium carbonate, potassium hydrogen citrate-
Citric acid, potassium dihydrogen phosphate-borax, disodium hydrogen phosphate-citric acid, etc. can be used.

As the polymerization initiator, a water-soluble, oil-soluble single type or redox type is used. For example, common water-soluble inorganic initiators such as persulfates can be used alone or in combination with sulfites, bisulfites, thiosulfates, etc. as redox initiators. Further examples include redox initiators such as organic hydroperoxide-sodium formaldehyde sulfoxylate, azo compounds, and the like.

The thermoplastic resin lubricant of the present invention can be mixed with a thermoplastic resin according to a commonly used method. The blending amount of the lubricant is 0.05 to 1O per 100 parts by weight of the thermoplastic resin.
Parts by weight. If the amount of lubricant is less than this range,
It is difficult to obtain a composition that has good moldability and gives a molded article with good gloss and transparency and little thermal coloring. Moreover, if it is larger than this range, moldability will be poor.

The thermoplastic resin of the present invention may contain stabilizers such as organotin compounds, lead-based, barium-based, and zinc-based metal soaps, and epoxy compounds; stearic acid, ester wax, and paraffin. Lubricants such as Wanx and stearyl alcohol; plasticizers such as phthalate esters, phosphoric acid esters, fatty acid esters, and epoxy systems; impact reinforcement agents such as MBS and HeBS; colorants such as carbon black and titanium oxide. ; Fillers such as calcium carbonate and asbestos:
Inorganic blowing agents such as ammonia carbonate and sodium bicarbonate may be blended, and organic blowing agents may include blowing agents such as nitro blowing agents, sulfohydrazide blowing agents, and azo blowing agents.

〔Example〕

In the following, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In addition, all "parts" in the examples indicate "parts by weight."

Further, the reduced viscosity ηsp/c of each polymer is (A).

(B) This is the value when each component was polymerized alone, and the ηsp/c value of each component was determined as follows. That is, each component is polymerized individually using a specified emulsifier, polymerization initiator, and polymerization temperature,
Create a calibration curve for ηsp/c using the chain transfer agent as a variable,
It was read from the calibration curve and defined as ηsp/c for each component.

Add 2 ions of ion-exchanged water to a reaction vessel equipped with a stirrer and a reflux condenser.
80 parts, 1.5 parts of sodium dioctyl sulfosuccinate, 4.0 parts of ammonium persulfate, 2.0 parts of n-octyl mercaptan, and 32 parts of butyl acrylate and 48 parts of styrene as components (A) were charged, and the inside of the container was filled with nitrogen. After replacing the air, the temperature of the reaction vessel was raised to 70"C while stirring.
The mixture was heated and stirred for hours. Subsequently, 20 parts of methyl methacrylate and 0.0 parts of n-octyl mercaptan were used as component (B).
05 parts of the mixture was added dropwise over 2 hours, and after the addition was completed, the mixture was further stirred for 2 hours to complete the polymerization. After cooling, the obtained emulsion was salted out using aluminum chloride, filtered, washed and dried to obtain a two-stage polymer.

Using the same reaction vessel as in Example 1, and under the same polymerization and coagulation conditions as in Example 1 under the conditions shown in Table 1, 2.
A stage polymer was prepared.

Comparative Flame Soil Technique Using the same reaction vessel as in Example 1, a polymer was produced under the same polymerization and coagulation conditions as in Example 1 under the conditions shown in Table 1.

In Comparative Example 5, the polymer aggregated (blocked) during the coagulation process.
However, due to problems with productivity, no evaluation was conducted.

Appropriate amounts of each polymer obtained under the conditions shown in Table 1 were added to 100 parts of polyvinyl chloride resin (average degree of polymerization 700), 1.5 parts of butyltin mercapto, 1.0 parts of epoxy auxiliary agent, and dibutyltin maleate. 0.5 parts and 3 parts of each of the above samples in a Henschel mixer to prepare examples of the present invention (Examples 1 to 1).
Vinyl chloride resin compositions of Example 0) and Comparative Examples (1 to 5) were obtained. The following evaluation was performed using this composition. In addition, as Comparative Example 6, polyvinyl chloride resin I without a lubricant was added.
J1 was similarly evaluated. The evaluation conditions are as follows, and the evaluation results are shown in Table-1.

Stickiness: Using 6 inch rolls, kneading temperature 205℃ x 200℃,
A sample of 100 g is kneaded with a roll spacing of 1 m+a, and the time required for the sheet to adhere to the roll surface and not peel off is measured.

The longer this time, the better the durability of slipperiness at high temperatures.

Brabender gelling properties: Tmax (min): Indicates the time to reach the maximum torque (kg-m) when measured using a Brabender plasticcorder; the larger the value, the slower the resin melts and the colder it is. big.

Mmax (kg-m): Maximum torque (kg-m); the lower this value is, the lower the melt viscosity of the resin is, and the greater the slipperiness.

Adhesion: Knead for 15 minutes and measure the adhesion of the resin to the vessel wall. The amount of adhesion is shown in %.

Measurement conditions: temperature 180″C1 rotation speed 30rpI11, filling amount 50g.

Fluidity: Using a 25φ-/ml 1-screw extruder, the extrusion amount for 3 minutes was measured under the following conditions. The larger the extrusion amount, the better the fluidity and the greater the slipperiness.

Temperature: C+ 160'C, Cz 170'C, C31
80'C, Gui 180''C: rotation speed 4Orpm.

Transparency: Using a 6-inch roll, roll kneading temperature 185°C x 18
A sample of 100g of sample was kneaded for 5 minutes at 0°C with an interval of 1mm, and then pressed under pressure (40kg) at 185°C to make a 2mm thick test piece, which was measured using an integrating sphere haze meter ( According to JIS-6714.

Below are 100 parts of each of the following thermoplastic resins mixed with 3 parts of the polymer obtained in Example 1, and 100 parts of each of the following thermoplastic resins. Mixed with a ξ mixer. Using an 1-screw extruder (25φm1m''), the resulting mixture was measured for the extrusion amount (g/l) for each resin at different temperatures as shown below.

n+in) A fluidity test was conducted. Moreover, the pressure (kg-m) during extrusion was measured. The larger the extrusion amount and the lower the pressure, the greater the slipperiness. The results are shown in Table-2.

(1) ABS resin (Diapet @ ABSl130Q
L, product name, manufactured by Mitsubishi Rayon ■) Molding temperature: C, = 180℃, Cz = 200"C, C5
-200℃, head = 200℃ 1 die-200℃ (2
) Styrene resin (Styrene NF-20; trade name, manufactured by Idemitsu Petrochemical ■) Molding temperature: c+=16oC, Cz=180oC, C,
= 200℃ 1 head = 200℃, die -210℃ (
3) Polycarbonate resin (Novarex 7022; trade name, manufactured by Mitsubishi Chemical Industries, Ltd.) Molding temperature: CI = 230°C, Cz = 260°C, C3 = 2
70'C, head -270'C, die -280°C (4
) Polyethylene resin (HIIXF 000F.

Product name, manufactured by Mitsui Petrochemical Industries, Ltd.) Molding temperature: C+=150℃, Cz=165℃, Ca=
1'? 5℃, head - 175℃ 1 die = 175'C
(5) Polyester resin (Dyanite@PA-200
;Product name, made by Mitsubishi Rayon■) Acid form temperature: C, = 280'C, (:z = 280°C
, (1 = 280℃, hend = 260℃ 1 die 260
'C(6) Hinyl chloride resin [Natsuhi pvc (P-70(
1)) Molding temperature: C, = 160°c, Cz = 1
70"C, C: -180"C, head -175°C, die -180'c or less margin Table 224 [Effects of the invention] As shown in the examples, the lubricant of the present invention was applied to various thermoplastic resins. By blending it, the mold releasability and lubricity during molding are superior to those of conventional products, and the fluidity during extrusion is increased, resulting in improved productivity. In addition, the molded product exhibits good transparency and gloss, and has little thermal coloring.

Claims (2)

[Claims] (1) (A) Reduced viscosity ηsp/c obtained by copolymerizing a monomer mixture consisting of 20 to 80% by weight of acrylic ester and 80 to 20% by weight of aromatic vinyl monomer (copolymer 0. Dissolve 1 g in 100 ml of chloroform and heat at 25°C.
(B) methyl methacrylate alone or other copolymerizable copolymerizable with 50 wt % or more of methyl methacrylate and 50 wt % or less of When 10 to 70 parts by weight of a monomer mixture consisting of monomers is polymerized with the methyl methacrylate or the monomer mixture alone, the reduced viscosity ηsp/c of the (co)polymer is 1.5 dl/g or less A lubricant for thermoplastic resins consisting of a two-stage polymer obtained by (co)polymerization so that (2) A thermoplastic resin composition comprising 100 parts by weight of a thermoplastic resin and 0.05 to 10 parts by weight of the lubricant for thermoplastic resins according to claim (1).