JPH03100011A - Manufacture of tapered graft copolymer of polybutadiene with alkylstyrene and alkyl methacrylate - Google Patents

Abstract

PURPOSE: To obtain a taper graft copolymerization product for improving impact strength at normal temperatures and low temperatures, low-temperature properties, processability, etc., of a PVC resin by the taper graft copolymerization of (alkyl)styrene or acrylonitrile and a (meth)acrylic acid ester to a polybutadiene(styrene) emulsion under specific conditions and the treatment of the polymer emulsion obtained.

CONSTITUTION: After an emulsifying agent and a polymerization initiator are added to a polybutadiene(styrene) emulsion as the major component, (alkyl)styrene or acrylonitrile is non-quantitatively and continuously added in the first stage in such a manner that the first introduction ratio is rendered high and the ones leading up to the final stage are gradually reduced and simultaneously, a (meth)acrylic acid ester is non-quantitatively and continuously added in such a manner that the introduction ratio of part of the (meth)acrylic acid ester is rendered small at first and the ones leading up to the final stage is gradually increased and then, after the remaining (meth)acrylic acid ester of the second stage is quantitatively and continuously added at a temperature slightly lower than the reaction temperature of the first stage, the polymer emulsion obtained by the taper graft copolymerization reaction of the above described each compound is further subjected to salting-out treatment, heat treatment, filtration and drying treatment.

COPYRIGHT: (C)1991,JPO

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a taper graft copolymer of butadiene polymer, alkyl styrene, and alkyl methacrylate, which is used as a modifier to improve the low-temperature physical properties of vinyl chloride resin. Relating to a method of manufacturing.

[Conventional technology]

PVC resin is chemical resistant, oil resistant, flame retardant, highly rigid,
Although it has excellent wear resistance, it is known to have poor impact resistance and processability. To improve this problem, methyl methacrylate butadiene styrene copolymer, or MBS resin, which is made by copolymerizing methyl methacrylate, butadiene, and styrene, has been used as a modifier for vinyl chloride resin. .

[Problem to be solved by the invention]

However, when MBS resin is used as a modifier for vinyl chloride resin, the impact resistance and processability at room temperature are improved, but the impact resistance at low temperatures is actually poor (and the transparency of the product is also poor). Therefore, there are many restrictions in terms of resin molding processing.

[Means to solve the problem]

The present invention uses butadiene or butadiene styrene latex as a main component, and reacts styrene, alkyl styrene, or acrylonitrile, and acrylic acid alkyl ester or methyl acrylic acid alkyl ester with this by taper graft copolymerization method. A method of producing a graft copolymer is provided.

When the taper graft copolymer of butadiene, alkyl styrene, and methacrylic acid furkyl ester obtained in this way is used as a modifier for vinyl chloride resin, it can be used as a modifier for vinyl chloride resin without impairing the original properties and characteristics of vinyl chloride. Depending on the amount blended, it is possible to improve the impact resistance of vinyl chloride resin at room temperature and low temperature, and improve transparency and emulsifying properties.

That is, the taper graft copolymerization reaction of the present invention is a normal emulsion polymerization, but its characteristics include first using polybutadiene or polybutadiene styrene latex as a main component, adding an appropriate amount of an emulsifier and a polymerization initiator, and first In one step, at a temperature of 40 to 85°C, one or more resins selected from styrene, alkylstyrene, and acrylonitrile and some acrylic acid alkyl ester or methyl acrylic acid alkyl ester resin are Quantitatively and continuously injected into the above main component mixture,
After that, in the second step, the remaining acrylic acid alkyl ester or methyl acrylic acid alkyl ester is quantitatively and continuously injected at a temperature slightly lower than the temperature in the first step to cause a copolymerization reaction of each of the above-mentioned compounds. This is a method for obtaining a taper graft copolymer of butadiene, alkyl styrene, and alkyl methacrylate.

Specifically, styrene or alkylstyrene is P
In the first step, all or most of the styrene or alkyl styrene is is required to be injected, and then a portion of the copolymerization required amount of acrylic acid alkyl ester or methyl acrylic acid alkyl ester is injected. When injecting styrene or alkylstyrene, the injection speed should be fast (,
The injection rate is gradually reduced towards the end of the period, and the injection is completed within about 2 hours. In this first step, particular care must be taken to inject some of the acrylic acid alkyl ester or methyl acrylic acid alkyl ester simultaneously with the injection of styrene or alkylstyrene as described above. This partial injection allows the acrylic acid alkyl ester or methyl acrylic acid alkyl ester subsequently injected in the second stage to be grafted relatively easily onto the outer layer of the same compound injected during the first stage. It's for a reason. The injection rate of this acrylic acid alkyl ester or methyl acrylic acid alkyl ester in the first stage should be as slow as possible at the beginning, and gradually become faster towards the end (it is better to complete the injection within 2 hours. A two-stage injection is started; in this stage, acrylic acid alkyl ester or methyl acrylic acid alkyl ester is injected in a fixed amount, and the injection is completed within about 2 hours.

In the present invention, the amount of styrene or alkyl styrene injected in the first step is 2 to 10 times, preferably 3 to 7 times, the amount of acrylic acid alkyl ester or methyl acrylic acid alkyl ester in the first step. The amount used is 5 to 35% of the total weight of the copolymerization reaction product. In addition, the injection rate ratio between the initial stage and the final stage is 2:1 to 5:1.
It is.

In the present invention, the total weight of the acrylic acid alkyl ester or methyl acrylic acid alkyl ester that is injected in the first stage and the second stage is 5 to 25% of the total weight of the copolymerization reaction product, but The total weight ratio of injection and the second stage is 0.2 to .1.

The injection rate ratio between the initial stage and the final stage in the first stage is 0.3~
It is 0.8.

In addition, the initial injection rate ratio of styrene, alkyl styrene, or acrylonitrile injected in the first stage of the present invention and acrylic acid alkyl ester or methyl acrylic acid alkyl ester injected in the same stage is 7 to 7.
15, and the end-stage infusion rate ratio is 0.7-4.

In addition, in the present invention, the first stage polymerization reaction temperature is 40
-85°C, preferably 60-70°C. The polymerization reaction temperature in the second stage is 35° to 80'C, and 55° to 65'C.
The temperature is preferably 0-15°C, particularly preferably 5-10°C lower than the temperature in the first stage.

A white powdery graft copolymer resin can be obtained by subjecting the polymer emulsion obtained after completion of the graft copolymerization to salting-out heat treatment, filtration, drying, and other treatments. If this is kneaded with a vinyl chloride resin and processed and molded, a product with improved impact resistance and processability at room and low temperatures of vinyl chloride can be obtained.

The polybutadiene or polybutadiene styrene emulsion used as the main component in the present invention has a solid content of 20 to 20%.
It is preferable that the particle size accounts for 50% and the particle size is 300 to 2000 particles. If the particle size becomes smaller than this, the impact strength will be affected. The amount of the main component used is 40 to 80% by weight based on the total weight of the copolymerization reaction product.

The emulsifier used in the present invention can be any emulsifier that is generally used in the production of synthetic rubber. These include sodium oleate, sodium stearate, sodium fatty acid, etc., and the amount of emulsifier used is 0 to IO% by weight based on the entire resin. In the copolymerization reaction process, in order to control the appropriate growth of particles, the type of polymerization initiator is usually selected and the amount used is adjusted, or electrolytes, inorganic salts, or organic salts are added during polymerization. Force u. Moreover, a crosslinking agent can also be used if necessary. By adding these initiators, etc., the particle size of the copolymer particles can be appropriately controlled.

There are no particular limitations on the polymerization initiator used in the present invention. Generally suspension polymerization, emulsion polymerization, solution polymerization,
Any oil-based or water-soluble initiator suitable for block polymerization can be used. These are selected from organic peroxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, tetramethylbutyl hydroperoxide, or inorganic initiators such as persulfates and perborates. Use one type or combination of various types. The amount of initiator used is o, oi to 5% by weight based on the total weight of the resin.

Further, electrolytes, organic salts or inorganic salts applicable to the present invention include, for example, sodium formaldehyde sulfoxylate,
There are sodium sulfate, iron sulfate, etc., and the amount used is 0.01 to 5% by weight based on the entire resin.

The copolymer emulsion obtained by performing the copolymerization reaction with the above compound in Graph I can be mixed with a mixture of hydrochloric acid and saline, an aqueous solution of hydrochloric acid, sulfuric acid, calcium chloride, magnesium chloride, aluminum sulfate, acetic acid, etc. and a salt. After passing through analysis treatment, heat treatment, filtration treatment, and drying treatment, a white powdery resin can be obtained.

〔Example〕

The present invention will be further explained in detail below with reference to Examples. Of course, the present invention is not limited to the following examples.

Styrene butadiene (
SB) The solids content of the emulsion is 23%.

Example 1 6000 g of butylene stadiene latex was charged into a 201 capacity stainless steel polymerization reactor, 1500 g of deionized pure water and 30 g of lithium oleate were added, and then cumene hydroperoxide was added as a polymerization initiator. Inject 8g at once and create a vacuum of 680 mm inside the device.
) After reducing the pressure to lg, nitrogen (N2) gas was introduced,
While maintaining a pressure of 0.4 kir/cm”, the temperature was increased to 65%.
Raise to ℃. The first stage of styrene injection will now begin, but first, the injection rate will be 12.5g/min for the first 40 minutes.
, then increase the injection rate to 8.75 g/min.
Continue to inject for about 40 to 80 minutes by reducing the injection rate to 5 g/n1in and continue injecting for about 80 to 1 in.
Make a 20 minute infusion. In other words, the injection process takes two hours from beginning to end. At this stage, at the same time as the styrene injection, a portion of methacrylic acid alkyl ester was injected at an injection rate of 1.5 g/rrIin for the first 60 minutes.
Inject at an injection rate of 3.5 g/min until 0 min, then add 4 g of cumene hydroperoxide, lower the temperature to 60 °C, and start the second stage of injection of methacrylic acid alkyl ester. The injection was carried out quantitatively and continuously at a rate of 2.5 g/min, and a total weight of 300 g of methacrylic acid alkyl ester was injected over 2 hours.

Example 2 6000 g of butylene stadiene latex was charged into the same polymerization reactor as in the previous example, and 1 liter of deionized pure water was added.
After introducing 500 g of sodium oleate, 30 g of sodium oleate, and 6 g of cumene hydroperoxide as an initiator, and reducing the pressure inside the device to a degree of vacuum of 680 nHg, nitrogen gas was supplied and the temperature was lowered while maintaining a pressure of 0.4 kg/cm. 70
℃ and begin the first stage of styrene injection. First, for the first 40 minutes, 12.5g/min, about 4
8.75g/min from 0 minutes to 80 minutes, about 80 minutes
At the same time, a portion of methacrylic acid alkyl ester was injected at a rate of 5 g/min for 120 minutes, and at an increased rate of 1 g/min for the first 60 minutes and from about 60 minutes to 120 minutes. Inject at a rate of .5 g/ll1in.

Then, 3 g of cumene hydroperoxide was added again, the temperature was lowered to 65°C, and the second stage of injection of methacrylic acid alkyl ester was quantitatively performed at a rate of 3.758/min. A total weight of 450 g of methacrylic acid alkyl ester was injected.

Example 3 Using the same reaction apparatus as in the above example, 6000 g of SB emulsion (styrene butadiene latex), 1500 g of deionized pure water, 30 g of sodium oleate, 6 g of divinylbenzene, and 5 g of cumene hydroperoxide were introduced into the apparatus. After reducing the pressure to a degree of vacuum of 680 maHg,
．． Supply nitrogen gas, raise the temperature by 70°C while maintaining a pressure of 0.4 kg/cm'', and then begin the first stage of styrene injection. 13.5 g for the first 40 minutes.
/+in, at a rate of 6 g/min from about 40 minutes to 80 minutes, and at a rate of 3 g/min from about 80 minutes to 120 minutes, and at the same time, a portion of methacrylic acid alkyl ester was injected at a rate of Ig/min for the first 60 minutes, about For 60 to 120 minutes, the injection amount was increased to 1.5 g/min, and then 4 g of cumene hydroperoxide was added again.
The temperature was lowered to 60° C., and the second stage of alkyl methacrylate was quantitatively injected at a rate of 58/min, with a total weight of 600 g of alkyl methacrylate being injected over two hours.

Comparative Example 1 In the same reactor as above, 6000 g of SB emulsion, 1500 g of deionized pure water, and 30 g of sodium oleate.
After introducing 5 g of cumene hydroperoxide, which is a g1 initiator, and reducing the pressure inside the device to a vacuum level of 680 mmHg, nitrogen was introduced, and the temperature was raised to 60 ° C while maintaining the pressure at 0.4 kg/cna''. After that, in the first stage, methacrylic acid alkyl ester was added at a rate of 6.25 g/min.
After continuously injecting cumene hydroperoxide at a constant rate of 750 g in 2 hours, 6 g of cumene hydroperoxide was added again.
In the second step, styrene was injected at a constant rate of 7.5 g/ml, and a total weight of 1900 g of styrene was obtained in 2 hours.

Comparative Example 2 The SB emulsion, deionized pure water, and sodium oleate were added in the same manner as in Comparative Example 1, but 1 g of cumene hydroperoxide as an initiator was added. Then, under the same vacuum degree, nitrogen introduction, pressure maintenance, and temperature conditions as above, methacrylic acid alkyl ester and styrene were simultaneously added at 4.4 g/min and 2.5 g/w, respectively.
The total amount of styrene was 11,050 g and the total amount of alkyl methacrylate was 600 g.

Table 1 shows the physical properties of the test pieces based on the above examples and comparative examples.

Bales 1) (1) Formula PVC (p=800) 100 parts MBS
10 parts octyltin mercaptide 1.6 parts glycerin partial fatty acid ester 0.9 parts complex ester wax o, 6 parts PMMA
1. t) Part (2) Roll conditions: Mixing roll 180'C x 5 minutes (3) Press conditions: 175℃ x 2.5 molecules after heating, pressure 80kg/■2 1
Press at 75°C for 1 minute.

(4) Thickness of test piece: 3 dragons (Note 1) Roller wrapping time: The mixture is wound on the surface of a 6" roller, and the time it takes until it contacts the roller and becomes gelatinous is shown.

Example 4 6700 g of SB emulsion was charged into a 20ρ stainless steel polymerization reactor, and then 1000 g of deionized pure water, 30 g of sodium oleate, 6 g of cumene hydroperoxy as an initiator, 3 g of divinyl betuzene, and trivalent dodecyl were added. Add 3g of mercaptan and heat the inside of the device to 680i.
After vacuuming to mHg, nitrogen gas was supplied and 0.4 kg
The temperature was raised to 65°C while maintaining the pressure at 1/cm", and then the first stage of styrene injection began.

For the first 40 minutes, the injection rate was 9 g/min. From about 40 minutes to 80 minutes, the injection rate was reduced to 6 g/min. From about 80 minutes to 120 minutes, the injection rate was further reduced to 3.75 g/min, and the injection rate was injected for 2 hours. A total of 750 g of styrene was injected. On the other hand, at the same time as the first stage of styrene injection, methacrylic acid furkyl ester was injected at a rate of 1.5 g/min for the first 60 minutes, approximately 60 g/min.
The injection amount was increased to 3.5 g/+in for 120 minutes to 120 minutes, and 300 g of methacrylic acid alkyl ester was injected for 2 hours.

After that, 4 g of cumene hydroperoxide was added again, and the temperature was lowered to 60°C. Then, the second stage of quantitative injection of methacrylic acid alkyl ester was carried out at a rate of 5 g/min for 2 hours, and the total weight was 600 g. The methacrylic acid alkyl ester was injected.

Example 5 The conditions for the injection ratio of styrene in the first stage from the addition of SB emulsion were almost the same as in Example 4, except that the injection rate of styrene in the first stage was 13.5 g/min for the first 40 minutes,
Approximately 40 minutes to 80 minutes: 6 g/min % Approximately 80 minutes to 12
At 0 minutes, the amount was gradually reduced to 3.5 g/win, and in 2 hours, 11,900 g of degenerated styrene was injected, and at the same time, part of the alkyl methacrylate was added to the initial 60
The injection rate was 1.5 g/min for about 60 to 120 minutes, and the rate was increased to 3.5 g/min. After injecting a total weight of 300 g of methacrylic acid alkyl ester in 2 hours, the injection rate was increased to 3.5 g/min. After adding 4 g of cumene and hydroperoxide and lowering the temperature to 60°C, the second stage of continuous quantitative injection of methacrylic acid alkyl ester was carried out at 2.5 g/m
1300 g of degenerated alkyl methacrylate was injected in 2 hours.

Example 6 The conditions for the three-step reduction injection ratio of styrene in the first stage from the injection of SB emulsion were the same as in Example 5, but the injection of alkyl methacrylate was carried out simultaneously with the injection of styrene in the first stage. The amount was 1 g/min for the first 60 minutes, then increased to 1.5 g/min for about 60 to 120 minutes, and methacrylic acid alkyl ester was injected at 15 g/min in 2 hours.
After injecting 0g, 3g of cumene hydroperoxide as an initiator was added again, and the temperature was lowered to 60°C, followed by continuous quantitative injection of methacrylic acid alkyl ester in the second stage.
The injection rate was 75 g/min, and 450 g of methacrylic acid alkyl ester was injected over 2 hours.

Comparative Example 3 6700 g of SB emulsion, 1000 g of deionized pure water,
30 g of sodium oleate and 5 g of cumene hydroperoxide as an initiator were each put into the same reactor as in the above example, and after reducing the pressure inside the device to a degree of vacuum of 680 mmHg, nitrogen gas was introduced to give a reaction mixture of 0.4 kg/cm2. The temperature was raised to 60°C while maintaining the pressure of 6.2
Continuous injection at a constant rate of 5g/nin, 750 in 2 hours
After injecting 5g of methacrylic acid alkyl ester, 5g of cumene hydroperoxide was added again, and the same 60"
6. Continuous metered injection of styrene in the second stage at a temperature of C.
At a rate of 25g/min, the total weight was 750g in 2 hours.
of styrene was injected.

Comparative Example 4 6700 g of SB emulsion, 1000 g of deionized pure water
, 30 g of sodium oleate and 6 g of cumene hydroperoxide as an initiator were each put into the reactor, and after reducing the pressure inside the device to a degree of vacuum of 680-■Hg, nitrogen gas was introduced to give a pressure of 0.4 kg/cm. The temperature was raised until the temperature reached 60°C while maintaining the pressure of ``.Thereafter, in the first stage, styrene was continuously injected at a rate of 7.5 g/min, and 900 g of styrene was injected in 2 hours. Then, 4 g of cumene hydroperoxide was added again, and at the same temperature, the second stage of quantitative continuous injection of methacrylic acid alkyl ester was carried out at a rate of 5 g/min.
0 g of methacrylic acid alkyl ester was injected.

Table 2 shows the physical properties of the test pieces obtained by these methods.

The distribution recipe, roll conditions, press conditions, test pieces, Note 1, etc. in this test were the same as those used in Table 1.

@2) 〔Effect of the invention〕

Claims (11)

[Claims] (1) Polybutadiene or polybutadiene styrene emulsion is the main component, and after adding an emulsifier and a polymerization initiator to this, first, in the first step, one type of compound selected from styrene, alkylstyrene, and acrylonitrile is added,
Continuous non-quantitative injection is performed so that the initial injection rate is high and the injection rate gradually decreases toward the end, and at the same time, a portion of the amount of acrylic acid alkyl ester or methacrylic acid alkyl ester used is injected into the initial injection. Continuously non-quantitatively inject acrylic acid alkyl ester or methacrylic acid at a slightly lower reaction temperature than in the first stage, and then inject acrylic acid alkyl ester or methacrylic acid in the second stage at a slightly lower reaction temperature than in the first stage. After continuous quantitative injection of the remaining amount of alkyl ester, a polymer emulsion was obtained by taper graft copolymerization reaction of each of the above compounds, and this emulsion was further subjected to salting out treatment, heat treatment, filtration and drying treatment. A method for producing a taper graft copolymer of polybutadiene, alkyl styrene, and alkyl methacrylate to obtain a taper graft copolymer of polybutadiene, alkyl styrene, and alkyl methacrylate. (2) The injection amount of one compound selected from styrene, alkyl styrene, and acrylonitrile in the first stage is 2 to 2 to the injection amount of acrylic acid alkyl ester or methacrylic acid alkyl ester injected in the same first stage. The method for producing a taper graft copolymer of polybutadiene, alkyl styrene, and alkyl methacrylate according to claim 1, wherein the copolymer is 10 times as large. (3) The polybutadiene and alkyl styrene according to claim 1, wherein the amount of the compound selected from styrene, alkyl styrene and acrylonitrile used in the first step is 5 to 35% of the total weight of the copolymerization reactants. , a method for producing a taper graft copolymer of an alkyl methacrylate ester. (4) The total weight of the acrylic acid alkyl ester or methacrylic acid alkyl ester injected in the first stage and the second stage is 5 to 25% of the total weight of the copolymerization reactants. A method for producing a taper graft copolymer of alkyl styrene and alkyl methacrylate. (5) The ratio of the injection amounts of the alkyl acrylate or alkyl methacrylate injected in the first stage and the second stage, respectively, is 0.2 to 1. A method for producing a taper graft copolymer of an acid alkyl ester. (6) The polybutadiene and alkyl styrene according to claim 1, wherein the ratio between the initial injection rate and the final injection rate of styrene, alkylstyrene, or acrylonitrile that is continuously injected in a non-quantitative manner in the first stage is 2 to 5. A method for producing a taper graft copolymer of styrene and alkyl methacrylate. (7) The ratio between the initial injection rate and the final injection rate of the acrylic acid alkyl ester or methacrylic acid alkyl ester that is continuously injected non-quantitatively in the first stage is 0.3 to
0.8. The method for producing a taper graft copolymer of polybutadiene, alkylstyrene, and alkyl methacrylate according to claim 1. (8) The ratio of the initial injection rate of styrene, alkyl styrene or acrylonitrile in the first stage to the initial injection rate of acrylic acid alkyl ester or methacrylic acid alkyl ester in the first stage is 7 to 15. Polybutadiene and alkylstyrene as described in
A method for producing a taper graft copolymer of an alkyl methacrylate ester. (9) The ratio of the final injection rate of styrene, alkylstyrene, or acrylonitrile in the first stage to the final injection rate of acrylic acid alkyl ester or methacrylic acid alkyl ester in the first stage is 0.7 to 4. 2. A method for producing a taper graft copolymer of polybutadiene, alkyl styrene, and alkyl methacrylate according to item 1. (10) The polymerization reaction temperature in the first stage is 40°C to 85°C
The polymerization reaction temperature of the second stage is 35°C to 80°C, and the former is 0° to 15°C higher than the latter. A method for producing an ester taper graft copolymer. (11) The optimal polymerization reaction temperature in the first stage is 60° to 70°C, and the optimal polymerization reaction temperature in the second stage is 55°C.
The method for producing a taper graft copolymer of polybutadiene, alkyl styrene, and alkyl methacrylate according to claim 1, wherein the temperature is 5° to 10° C. higher than the latter.