JPH039237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper quality improving composition comprising a cationic acrylamide polymer obtained by polymerizing acrylamide in the presence of a polymer latex. More specifically, in order to cationize the acrylamide polymer, a vinyl monomer having a cationic functional group is copolymerized, and then the acrylamide unit is cationically modified, or acrylamide etc. is polymerized and then the acrylamide unit is formed. This invention relates to a composition for improving paper quality obtained by cationically modifying. Cationic paper quality improvers conventionally used in the paper industry to improve water properties, yields, and paper quality in dry conditions include cationically modified starch, partial mannificates of polyacrylamide, and partial Hofmanns of polyacrylamide. There are reactants and copolymers of acrylamide and cationic vinyl monomers. However, when these are used as internal paper quality improvers in paper manufacturing, they improve general strengths such as surface strength, bursting strength, and tensile strength (of which bursting strength is a typical example), but on the contrary, they improve tear strength. has the disadvantage of reducing The present inventors have discovered the advantages of using the cationic paper quality improver in the paper manufacturing process:
It takes advantage of the effects related to coagulation and agglomeration, such as the effect of improving the retention of fine fibers and fillers, and the function of improving the general strength of paper, while not reducing the tear strength.
In addition, as a result of intensive research to find a cationic or amphoteric composition for improving paper quality that has an excellent function of improving size properties, it was found that the glass transition temperature
A composition for improving paper quality, which is a cationic acrylamide polymer containing a polymer latex obtained by polymerizing acrylamide as an essential monomer in the presence of a polymer latex at 60°C or lower, satisfies the above objectives. I found that it is possible to That is, in the present invention, in the presence of a polymeric latex [A] with a glass transition temperature of 60°C or lower, 1% and 5 to 45% by weight of a polymeric latex [A] with a glass transition temperature of 60°C or lower, A polymer composition obtained by polymerizing 95 to 55% by weight of a vinyl monomer, wherein the vinyl monomer contains 30 to 3 mol% of a cationic vinyl monomer and the remaining Cationic acrylamide polymer composition [B-1] using a vinyl monomer other than a cationic vinyl monomer whose main component is acrylamide in 70 to 97 mol%, 2. Glass transition In the presence of 5 to 45% by weight of polymeric latex [A] at a temperature of 60°C or less, 95 to 55% by weight of vinyl monomers other than vinyl monomers having cationic properties, the main component of which is acrylamide. %
A cationic acrylamide polymer composition [B −
2], 3 In the presence of 5 to 45% by weight of polymeric latex [A] with a glass transition temperature of 60°C or less, a cationic polymer whose main components are a cationic vinyl monomer and acrylamide is added. A polymer composition obtained by further cationically modifying a polymer composition obtained by polymerizing 95 to 55% by weight of vinyl monomers other than vinyl monomers, which A cationic acrylamide polymer composition modified so that 3 to 30 mol% of the total mol% calculated as monomers has cationic properties [B-
3] A composition for improving paper quality characterized by comprising any one of the following raw material compositions. More specifically, for example, (a) the above composition in which the cationic acrylamide polymer is obtained by polymerizing acrylamide and a cationic vinyl monomer; (b) the cationic acrylamide polymer; (c) The cationic acrylamide polymer is a vinyl monomer having cationic properties with acrylamide. There are the above-mentioned compositions in which the acrylamide unit is cation-modified after the copolymerization, but the composition is not necessarily limited to these as long as the above conditions are met. The polymer latexes used in the present invention are styrene-butadiene (hereinafter referred to as SBR), methyl methacrylate-butadiene (hereinafter referred to as MBR), and methyl methacrylate-styrene-butadiene (hereinafter referred to as MBR) obtained by known polymerization methods.
(hereinafter referred to as MSBR), acrylonitrile-butadiene type (hereinafter referred to as NBR), chloroprene type (hereinafter referred to as NBR),
Synthetic rubber latex such as isoprene-based (hereinafter referred to as IR) and polybutadiene (hereinafter referred to as PB), emulsion latex such as vinyl acetate-based emulsion, vinyl acetate-acrylic acid ester emulsion, vinyl chloride and acetic acid These include vinyl chloride latex made from vinyl or ethylene as the main raw materials, vinylidene chloride latex made from vinylidene chloride and (meth)acrylic acid ester, and (meth)acrylic acid ester latex. In addition to the above-mentioned main raw materials, monomers that can be copolymerized with these main raw materials are often used in the latex in order to improve the physical properties of the obtained polymer latex, and such polymer latexes are also used in the present invention. Needless to say, it can be used as a polymer latex. Note that (meth)acrylic acid ester is an ester of acrylic acid or methacrylic acid and typically the following alcohols. That is, esters of other alcohols include methyl alcohol, ethyl alcohol, butyl alcohol, ethylene glycol, 2-ethylhexyl alcohol, etc., but needless to say, the same applies to esters of other alcohols. Monomers that can be copolymerized with the main raw material of the polymer latex include the following, but these are only representative examples; there are also other monomers that can be copolymerized with the main raw material. It goes without saying that all monomers can be used. That is, ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid and crotonic acid, conjugated diophine such as butadiene, isoprene and chloroprene, aromatic vinyl compounds such as styrene and methylstyrene, meth)acrylic acid ester, acrylonitrile,
Ethylene nitrile compounds such as methacrylonitrile, acrylamide, methacrylamide, N-
(Meth)acrylic acid amide type compounds such as methylol or N-methoxymethylacrylamide, N-methylol or N-methoxymethylmethacrylamide, N-butoxymethylacrylamide, monomers such as vinyl acetate, vinyl chloride, and vinylidene chloride. . Further, the glass transition temperature of the polymer latex used in the present invention must be 60°C or lower, preferably 40°C or lower. The reason why this glass transition temperature was limited to 60℃ or less is
This is because it is necessary to prevent a decrease in tear strength and improve sizing of paper obtained by adding the composition for improving paper quality according to the present invention. The lower limit of this temperature is −
Although temperatures up to about 90°C are possible, temperatures below -10°C may cause problems in terms of how easily the paper gets stained, so it is usually better to avoid it. The glass transition temperature (Tg) of the copolymer is a temperature calculated by the following formula []. 1/(Tg+273)=ΣWi/(Tgi+273) (Wi is the weight composition fraction of each comonomer, Tgi is the glass transition temperature of the homopolymer of each comonomer) Used as a raw material in the present invention Acrylamide may be commercially available and used industrially in the form of powder or aqueous solution. The cationic vinyl monomer is a monomer that can be copolymerized with acrylamide, such as dimethylaminoethyl memethacrylate, trimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, triethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, Trimethylaminopropyl methacrylate, 2-hydroxy-3-
Typical examples include methacrylic acid esters having an amino group such as methacryloxypropyltrimethyl, their sulfates or hydrochlorides, and their acrylic acid derivatives, and not only one type of these but also two or more types can be used in combination. A method of copolymerizing acrylamide or acrylamide with a cationic vinyl monomer in the presence of a polymeric latex and then further cationically modifying it involves adding an amino compound to the acid amide group of acrylamide using formaldehyde. A typical method is a method using the Mannitz reaction, but other methods such as the Hofmann reaction may also be used. In this case, the number of acid amide groups in the polymer decreases by the number of moles subjected to cation modification, and conversely, the number of cationic functional groups increases by the number of moles subjected to cation modification. Typical amino compounds used in the Mannitz reaction are dialkyl monoamines such as dimethylamine, diethylamine, dipropylamine, etc., and at least one of them is used, but other amino compounds can of course be used. However, from the viewpoint of composition stability, primary monoamines and polyamines account for 10% of the number of amino groups in all amino compounds.
The following is better. Further, the formaldehyde is generally industrially used formalin or industrially used paraformaldehyde. In the Hoffman reaction, sodium hypochlorite and
Sodium hydroxide, potassium hydroxide, etc. are used as the alkali. In the composition of the present invention, when polymerizing the acrylamide copolymer, in addition to acrylamide or a vinyl monomer having cationic properties with acrylamide, these may be added as necessary to the extent that the object of the present invention is not impaired. You may copolymerize with other monomers that can be copolymerized in an aqueous solution system. Representative examples of such monomers include unsaturated nitriles such as acrylonitrile and methacrylonitrile, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid,
Unsaturated carboxylic acids such as crotonic acid, lower alkyl esters and lower hydroxyalkyl esters of these acids, alkali or ammonium salts of these acids, styrene, methylstyrene,
One or more types of vinyl esters such as vinyl acetate can be used. In the present invention, the solid content weight ratio of A:(B-A) is limited to 5:95 to 45:55 for the following reasons. That is, in paper obtained using a composition in which the amount of polymer latex used is less than the specified range, the effects of preventing a decrease in tear strength and improving sizing cannot be observed. Furthermore, if the amount of polymer latex used is greater than the specified range, the paper obtained using it will not be sufficiently effective in improving general strength, that is, surface strength, bursting strength, and tensile strength. This ratio is preferably 10:90~
It's 40:60. Also, the molar ratio of (non-cationic polymer unit): (cationic polymer unit) in (B-A)
The reason for limiting it to 97:3 to 70:30 is as follows. That is, the amount of cationic polymerized units is the amount of fixing functional groups that are adsorbed to pulp fibers and fixed when the paper quality improving composition of the present invention is added to pulp slurry in the paper manufacturing process, whereas the amount of non-cationic polymerized units is The amount of ionic polymerized units has a general strength-enhancing effect on the paper.
If the former, which is the amount of fixing functional groups, is less than the limited amount, the fixing power to pulp fibers will be small, and the effects of improving paper quality and improving water resistance and retention will be insufficient, making it difficult to achieve the purpose of the present invention. Can not. On the other hand, if the amount is greater than the amount limited in the present application, the fixing power, water resistance, and retention improvement effects will further increase, but the latter, which has an effect of improving the general strength of paper, will be relatively reduced, and in this case, the paper quality improvement effect will also increase. is insufficient;
The problem lies in the inability to achieve the object of the present invention. Note that this ratio is preferably 95:5 to 75:25. In the composition of the present invention, even if a composition obtained by simply mixing A and a composition produced in the absence of the polymer latex [A] is added to the pulp slurry, the polymer latex [A] The components are not sufficiently fixed in the pulp, and the paper quality improving composition obtained according to the present invention is added to the pulp slurry to obtain high general strength and sizing improvement effects, as in the case of additive paper, but at the same time, tear strength is reduced. No effect on preventing the decrease in The reason for this difference is thought to be that the above monomers are partially graft-polymerized to the acrylamide latex particles in the presence of the polymeric latex in order to obtain the composition of the present invention. In the present invention, a known polymerization method for producing a water-soluble polymer containing acrylamide as a main component can be used to polymerize a monomer such as acrylamide in the presence of a polymer latex. That is, the total concentration of the solid content of the polymer latex, acrylamide, acrylamide, a cationic vinyl monomer, and other monomers is usually 5 to 25%.
It is preferable to carry out the polymerization in an aqueous system of % by weight. The temperature of polymerization is usually in the range of 30 to 100°C. Polymerization is initiated by potassium, sodium or ammonium salts of persulfate,
Polymerization can be carried out using only a peroxide such as hydrogen peroxide, or by so-called redox polymerization using the above peroxide in combination with a reducing agent such as acidic sodium sulfite or sodium thiosulfate. In this case, a compound having a large chain transfer constant such as isopropyl alcohol or tertiary-butyl alcohol may be added as a molecular weight regulator for polymerization. The polymerization time is usually in the range of 30 minutes to 5 hours, with the time required for the polymerization yield of the raw material monomers to reach 95% or more. In the present application, the Mannitz reaction carried out as one of the methods for introducing cationic polymerizable units is usually 40
At ~60℃, the process is completed within 20 minutes to 2 hours.
If the formaldehyde used and the active hydrogen of the dialkyl monoamine or all the amino groups are equimolar, cationic polymer units will be introduced by approximately the number of moles used, but in this case, the storage stability of the paper quality improving composition obtained is generally bad. Therefore, the amount of dialkylamine or other amino compound normally used is such that the reaction is carried out in such a range that the active hydrogen of all the amino groups is 1.1 to 1.5 times the mole of formaldehyde used to ensure storage stability. In this case, the amount of cationic polymerized units introduced is approximately equal to the number of moles of formaldehyde used. In addition, in the present invention, the Mannitz reaction is
Since the pH of the reaction system is 9 to 11 depending on the alkalinity of the dialkylamine or other amino compound used, a hydrolysis reaction of acid amide groups and ester bonds occurs as a side reaction simultaneously with the introduction of the cationic functional group. It is also a reaction in which a carboxyl group having anionic properties is generated, imparting anionic and anionic amphoteric properties, that is, amphoteric properties. In particular, this side reaction, hydrolysis reaction, often occurs when Mannitz reaction operations are carried out at high temperatures and for long periods of time. Increasing the number of anionic carboxyl groups by increasing the hydrolysis reaction reduces the aqueous property and retention property improvement effect, which are the characteristics of the paper quality improving composition of the present invention, and furthermore, the paper quality improvement effect is insufficient. Make it. Therefore, the Mannitz reaction generally requires a reaction temperature of 40 to 60°C.
C. and a reaction time of 30 minutes to 1.5 hours is preferred. When the paper quality improving composition of the present invention does not undergo cationic modification, the composition is prepared by mixing acrylamide with a cationic vinyl monomer and other monomers in the presence of a polymeric latex. PH inside is 4
7 by adding a mineral acid such as hydrochloric acid or sulfuric acid or an organic acid such as formic acid or acetic acid, and then polymerizing by adding a radical polymerization initiator. The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.
In the following, parts, percentages, and ratios are based on weight unless otherwise specified. Examples Styrene 25%, Methyl methacrylate 10%, Butyl acrylate 58%, β-hydroxyethyl methacrylate 2%, Methacrylic acid 2%, Acrylamide 3
Acrylic acid ester latex with a solid content of 45% and a pH of 6.8 (glass transition temperature is -1
℃), 628.6 g of distilled water, 237.0 g of 40% aqueous acrylamide solution, and 13.1 g of diethylaminoethylaminoethyl methacrylate were placed in a flask equipped with a cooling tube, stirrer, and thermometer, and while stirring, 13 g of 20% hydrochloric acid was added. Added. Then, heat is applied to raise the temperature of the liquid in the flask to 43°C. 10% on this
6.5 g of ammonium persulfate aqueous solution and 3.9 g of 10% acidic sodium sulfite were added, and a copolymerization reaction was carried out for 2.0 hours. After that, the temperature of the liquid in the flask was adjusted to 45℃, and 11.4 g of 37% formaldehyde aqueous solution (hereinafter referred to as 37% formalin) and 40% dimethylamine were added.
After charging 19.8% and carrying out Mannitz reaction for 1.0 hour, the temperature of the internal liquid was cooled to 20°C to obtain 1000 g of the paper quality improving composition (hereinafter referred to as the composition) of the present invention. The powder is a milky white viscous aqueous solution with a solid content of approximately 15% and a Burckfield viscosity of 25°C.
It was 4300 centipoise. Example 133.3 g of vinylidene chloride latex (glass transition temperature: 32°C) with a solid content of 45% and a pH of 6.8, consisting of 60% vinyl chloride and 40% vinylidene chloride, and distilled water.
634.9g and 207.8g of 40% acrylamide aqueous solution
Pour the mixture into a flask equipped with a cooling tube, stirrer, and thermometer, and perform the following operations while stirring. First, heat the liquid in the flask to 44°C. then 10
% ammonium persulfate aqueous solution and 2.4 g of 10% acidic sodium sulfite aqueous solution were added, and a polymerization reaction was carried out for 2.0 hours. After that, the temperature of the liquid in the flask was adjusted to 45℃, 6.6g of 37% formalin and 11.0g of 40% dimethylamine aqueous solution were added, and the Mannitz reaction was carried out for 1.0 hour, and then the liquid in the flask was cooled to 20℃. 1000 g of the paper quality improving composition (hereinafter referred to as composition) of the present invention was obtained. This is a milky white viscous aqueous solution with a solids content of approximately 15% and a Burckffield viscosity of 25.
It was 5040 centipoise in °C. Example 30 g of MSBR latex with a solid content of 50% and a pH of 6.5 (glass transition temperature is -1°C) consisting of 30.0% styrene, 30.0% methyl methacrylate, 38.5% butadiene, and 1.5% acrylic acid, 646.8 g of distilled water, 40%
194.1 g of acrylamide aqueous solution and 57.4 g of diethylaminoethyl methacrylate were put into a flask equipped with a condenser, a stirrer and a thermometer, and 57.0 g of 20% hydrochloric acid was added while stirring. Next, the temperature of the liquid in the flask was raised to 40°C, and 7.0 g of a 10% ammonium persulfate aqueous solution and 4.2 g of a 10% acidic sodium sulfite aqueous solution were added to carry out a copolymerization reaction for 2.0 hours. Then, while cooling the liquid temperature in the flask to 20℃, 20%
3.5 g of an aqueous solution of caustic soda was added to adjust the pH of the liquid in the flask to 6.5 to obtain 1000 g of the paper quality improving composition (hereinafter referred to as the composition) of the present invention. This was a milky white viscous aqueous solution with a solids content of about 15% and a Burckfield viscosity of 4800 centipoise at 25°C. Comparative Example 1 As a comparative example, 841.9 g of distilled water used in the example was replaced with distilled water in order to avoid using an acrylic ester latex and to make the solid content concentration of the final reactant approximately 15%.
800 g of a reactant containing no polymer latex (hereinafter referred to as Comparative Composition 1) was obtained in exactly the same manner as in the example except that 495.3 g was used. This was a clear viscous liquid with a solids content of approximately 15% and a Burckfield viscosity of 3850 centipoise at 25°C. Comparative Example 2 After obtaining 933.3 g of a reactant containing no polymer latex in the same manner as in the example except that the acrylic ester latex was not used, 1000 g of a composition (hereinafter referred to as Comparative Composition 2) simply mixed with 66.7 g of a polymer latex having the same composition and physical properties as the acrylic ester latex prepared above.
I got it. This is a milky white viscous aqueous solution with a solids content of approximately 15% and a Burckffield viscosity of 3200 at 25°C.
Although the temperature was centipoise, two layers separated after long-term storage (about 1 month). Comparative Example 3 An example is shown in which the glass transition temperature of the polymer latex used in the present invention exceeds the range of the present invention. Glass transition temperature used in Examples -1°C
Instead of the acrylic ester latex, we used an acrylic ester with a glass transition temperature of 69°C, solid content of 45%, and pH 6.8, consisting of 40% styrene, 42% methyl methacrylate, 3% acrylic acid, and 15% butyl acrylate. 1000 g of a composition of a comparative example (hereinafter referred to as comparative composition 3) was obtained under the same conditions and operations as in the example except that latex was used. This was a milky white viscous aqueous solution with a solids content of approximately 15% and a Burckfield viscosity of 4500 centipoise at 25°C. Comparative Example 4 This example shows a case where the ratio of the amount of acrylic ester latex used in the example exceeds the range of the present invention. 166.7 g of acrylic ester latex with the same composition and physical properties as the polymer latex used in the example, 644.7 g of distilled water, 148.1 g of 40% acrylamide aqueous solution, and 8.2 g of diethylaminoethyl methacrylate were placed in a tube equipped with a cooling tube, a stirrer, and a thermometer. of 20% hydrochloric acid while stirring.
Add 8.0g. Next, the flask was heated to 43° C., and 3.0 g of a 10% aqueous ammonium persulfate solution and 1.8 g of a 10% aqueous acidic sodium sulfite solution were added thereto, followed by a polymerization reaction for 2.0 hours. After that, adjust the liquid temperature in the flask to 45℃, and add 37% formalin 7.1.
g and 112.4 g of a 40% dimethylamine aqueous solution were charged, and the Mannitz reaction was carried out for 1.0 hour. After that, the temperature of the liquid in the flask was cooled to 20°C, and a composition of a comparative example (hereinafter referred to as Comparative Composition 4) was prepared. ) 1000g was obtained. This is a milky white viscous aqueous solution with a solid content of approx.
15%, the Burckffield viscosity was 1250 centipoise at 25°C. Comparative Example 5 In the example, a case where the amount of cationic functional groups exceeds the range of the present invention will be shown. 66.7 g of acrylic ester latex with the same composition and physical properties as the polymer latex used in the examples, 628.3 g of distilled water, and 198.5 g of 40% acrylamide aqueous solution.
g and diethylaminoethyl methacrylate 10.9
g into a flask equipped with a condenser, stirrer, and thermometer, and while stirring, add 10.5 g of 20% hydrochloric acid. Next, heat the liquid in the flask to 43℃, then add 5.4 g of 10% ammonium persulfate aqueous solution and 10%
3.3 g of an acidic sodium sulfite aqueous solution was added to carry out a polymerization reaction for 2.0 hours. After that, the temperature of the liquid in the flask was set to 45
After adjusting the temperature to
The mixture was cooled to 20° C. to obtain 1000 g of a comparative composition (hereinafter referred to as Comparative Composition 5). This product was a milky white viscous aqueous solution with a solids content of about 15% and a Burckfield viscosity of 2800 centipoise at 25°C. Comparative Example 6 A case in which no cationic functional group is introduced in the example will be shown. 66.7 g of an acrylic ester latex with the same composition and physical properties as the polymer latex used in the example, 624.4 g of distilled water, and 300.0 g of a 40% aqueous acrylamide solution were placed in a flask equipped with a cooling tube, a stirrer, and a thermometer, and stirred. While doing so, perform the following operations. First, heat the liquid in the flask to 42°C. Next, 4.0 g of a 10% aqueous solution of ammonium persulfate and 2.4 g of a 10% aqueous solution of sodium acid sulfite.
was added to carry out the polymerization reaction for 2.0 hours. Thereafter, 2.5 g of a 20% aqueous sodium hydroxide solution was added to adjust the pH to 6.0 after the completion of the polymerization reaction, and at the same time, the mixture was cooled to 20° C. to obtain 1000 g of a comparative composition (hereinafter referred to as Comparative Composition 6). This is a milky white viscous aqueous solution with a solids content of approximately 15% and a Burckfield viscosity of 25%.
It was 4200 centipoise in °C. Application Examples The usefulness of the paper quality improving compositions of the present application obtained in Examples ~ will be described below by comparison with the compositions obtained in Comparative Examples 1 to 6. Freeness (hereinafter referred to as CSF) 430 as shown by the Canadian standard water tester specified in JIS P8121
ml/CSF pulp N/BKP 10g bone dry and beating degree 430ml/CSF pulp L/BKP 10g bone dry
Mix and disperse in a disintegrator for 2 minutes using water from step 2. Next, 10 ml of an aqueous solution of a commercially available rosin-based sizing agent diluted to 1.0% was added, and after stirring for 2 minutes.
Add 1.5ml of 20% aluminum sulfate aqueous solution
Stir for 1 minute. Then, add 6g of the composition to 90% water.
diluted to 1.0 g to make an aqueous solution with a solid content of approximately 1.0%.
ml was added and stirred for 2 minutes to obtain a composition-added pulp slurry. First, in order to confirm the water content of the pulp slurry added with the composition and the cohesive properties such as retention, the water content by CSF is measured. That is, 333 ml of the composition-added pulp slurry was placed in a measuring cylinder, water was added thereto to adjust the volume to 1000 ml, and the water content by CSF was measured. Next, paper sheets were formed using a part of the pulp slurry containing the composition in a square sheet machine, and after press dehydration for 15 minutes under a pressure of 3.0 kg/cm ² , paper sheets were dried for 2 minutes in a drum dryer at 110°C. After drying, season it for 24 hours at a constant temperature of 20℃ and constant humidity of 65%. The basis weight of the composition-added paper thus obtained was 100 g/m ² . Below, the water content and additive paper for each were obtained under exactly the same conditions and operations as when using the compositions, except that Compositions ~ or Comparative Compositions 1 to 6 were used instead of the compositions above. . At the same time, as a control experiment, the water content was measured under the same conditions and operations as above, except that no composition was added, and paper without the addition of the paper quality improving composition was obtained. The specific bursting degree, specific tearing degree, and sizing degree of the obtained various additive papers and additive-free papers were measured. Specific rupture degree was determined according to JIS P8112, specific tear degree was determined according to JIS P8116, and size degree was determined according to JIS P8112. Table 1 shows the results of these tests and the compositions of the compositions used for each. The composition for improving paper quality obtained by the present invention maintains high aqueous properties, and the paper to which it is added exhibits high strength in both specific bursting and tearing properties, and at the same time has an excellent sizing effect. is obvious. 【table】

Claims (1)

[Scope of Claims] 1. A polymer obtained by polymerizing 95 to 55% by weight of a vinyl monomer in the presence of 5 to 45% by weight of a polymer latex [A] with a glass transition temperature of 60°C or lower. The composition comprises 30 to 3 mol% of the vinyl monomer having cationic properties and the remaining 70% by mole.
A cationic acrylamide polymer composition [B-1] using a vinyl monomer other than a cationic vinyl monomer whose main component is acrylamide in ~97 mol%. 2 Polymer latex with a glass transition temperature of 60°C or lower [A] In the presence of 5 to 45% by weight, a vinyl monomer other than a cationic vinyl monomer containing acrylamide as a main component 95 An acrylamide-based polymer composition obtained by polymerizing ~55% by weight,
3 to 3% of the total mole% converted as vinyl monomers
A cationic acrylamide polymer composition [B-2] in which 30 mol% was modified with cations. 3 Polymer latex with a glass transition temperature of 60°C or less [A] In the presence of 5 to 45% by weight, a cationic vinyl monomer and acrylamide are the main components. A polymer composition obtained by further cationically modifying a polymer composition obtained by polymerizing 95 to 55% by weight of a vinyl monomer other than the monomer, wherein the vinyl monomer A cationic acrylamide-based polymer composition [B-3] modified so that 3 to 30 mol% of the total mol% calculated as a polymer has cationic properties. A paper quality improving composition comprising a raw material composition containing any one of the following.