JPS59164355A - Polymer composition - Google Patents

Abstract

PURPOSE:To provide a polymer compsn. having good adhesion, strength and protective colloidal properties inherent to PVA as well as good water resistance and pigment-dispersibility inherent to casein, consisting of casein and a modified PVA into which a specified quantity of a specified long-chain alkyl group is introduced. CONSTITUTION:A polymer compsn. consists of 1-99wt% water-soluble long- chain alkyl group-modified PVA contg. 0.05-10mol% of a 4-20C long-chain alkyl group and 99-1wt% casein. If faults in PVA and casein can be covered without detriment to advantages inherent to each of them, it can be expected to increase the range of their use. However, they are poorly compatible with each other so that no combined effect could be obtd. When said modified PVA is used, there can be obtd. a compsn. having good adhesion, strength and protective colloidal properties inherent to PVA without detriment to good water resistance, pigment- dispersibility, etc. inherent to casein.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polymer composition comprising long-chain alkyl group-modified polyvinyl alcohol and casein.

Polyvinyl alcohol (hereinafter abbreviated as PVA) is a water-soluble polymer that exhibits excellent physical properties such as adhesive strength, strength, and protective colloidal properties, but it has poor compatibility with hydrophobic polymers and its protective colloidal properties are poor. It has the following drawback. Also,
Water resistance, ability to disperse pigments, dyeability, etc. are also insufficient.

On the other hand, casein is a natural polymer that has physical properties such as excellent pigment dispersion ability, dyeability, and water resistance, and is used in fields such as paper manufacturing and textiles, despite being expensive. However, casein has problems in terms of mechanical properties, perishability, heat resistance, and quality stability.

Therefore, if the advantages of PVA and casein can be combined with the disadvantages of both without combining them with FM, it is expected that the applications for paper manufacturing, textile industries, etc. will further expand.

However, PVA has poor compatibility with casein.

If these compositions are dissolved in water, they will separate or the formed film will become non-uniform, and the expected effect will not be achieved.On the contrary, the excellent physical properties of both will be impaired, and the desired combined effect of 2M will not be achieved. The problem was that I couldn't get it.

In view of this situation, the present inventors have conducted intensive research to solve the above-mentioned problems with compositions consisting of PVA and casein, and have found that they have developed a modified PVA in which a specific amount of a specific long-chain alkyl group has been introduced. When using PVA, the resulting composition has the advantage of PVA's adhesion.

The present invention was based on the fact that casein has properties such as strength and protective colloidal properties, as well as properties such as water resistance and ability to disperse pigments, which are the advantages of casein, without impairing practical use.

That is, the present invention contains 0.05 to 10 mol % of long chain alkyl groups having 4 to 2 o carbon atoms, and water-soluble long chain alkyl group-modified PVA (A) 1 to 99 weight % casein ( B) A polymer composition consisting of 99 to 1% by weight.

Long-chain alkyl group-modified PVA constituting the composition of the present invention
(hereinafter abbreviated as modified PVA) has 4 to 20 carbon atoms,
Preferably 6 to 20 long chain argyl groups and 0.05 to 10
% by mole and is water-soluble.

Such a modified Pν^ can be created by the following method, for example.

(1) A method of copolymerizing a vinyl ester (particularly preferably vinyl acetate) and an α-olefin having 4 to 20 carbon atoms, followed by saponification.

(2) A method of copolymerizing a vinyl ester (particularly preferably vinyl acetate) and an alkyl vinyl ester whose alkyl group has 4 to 2 carbon atoms, followed by saponification.

(3) A method of copolymerizing a vinyl ester (particularly preferably vinyl acetate) with an alkyl vinyl ether whose alkyl group has 4 to 2 carbon atoms, followed by saponification.

(41 A method in which a compound having an alkyl group having 4 to 2 carbon atoms that can react with the hydroxyl group of PVA or the ester group of polyvinyl ester is reacted with PVA or polyvinyl acecool. For example, acetalization.

Examples include esterification and etherification.

(51 A method of grafting a hydrophobic monomer having a noalkyl group with 4 to 20 carbon atoms in the presence of PVA or polyvinyl ester.

Among these methods for producing modified PVA, (11, (21
Methods (3) and (3) are particularly practical.

When the number of carbon atoms in the long chain alkyl group is less than 4, the effect of the present invention is insufficient, probably due to weak hydrophobicity, and the compatibility between modified pvA and casein is poor. On the other hand, when the number of carbon atoms exceeds 20, the hydrophobicity becomes too strong and the water solubility decreases, which is not preferable. Long chain alkyl group with 4 to 2 carbon atoms is modified PV
The proportion in A is 0.05 to 10 mol%, preferably 0.05 to 2 mol%.

If the proportion is less than 0.05 mol%, the compatibility between the modified Pv^ and casein is insufficient, while if it exceeds 10 mol%, it becomes insoluble in water, which is not preferable.

The degree of saponification of modified PVA is 50 to 100 mol%, since water solubility tends to decrease if it becomes too low.

In particular, it is preferably 80 to 100 mol%.

In the present invention, as the modified Pv^, a product obtained by copolymerizing a small amount of a third component such as an unsaturated carboxylic acid or an unsaturated sulfonic acid can also be used.

The casein constituting the composition of the present invention includes:

Examples include acid casein called lactic acid casein, hydrochloric acid casein, or sulfate casein, rennet casein, or modified substances thereof, which are soluble in water or an alkaline aqueous solution, but acid casein is particularly preferred.

The mixing ratio of modified Pv8 and casein in the composition of the present invention is 1:99 to 99:1 by weight, but in order to effectively exhibit the characteristics of the two components, it is 1° = 90 to 90:10. ．． In particular, a ratio of 30:0 to 70:30 is preferable. In the composition of the present invention, those in which the proportion of modified PVA is 50% by weight or more have the ability to disperse pigments while maintaining the excellent physical properties of modified Pv^, and the ability to improve the mechanical stability of latex.1 Dyeing property On the other hand, those with a proportion of modified PVA of less than 50% by weight maintain the excellent pigment dispersion ability and dyeing properties of casein, while improving the ability to adjust the viscosity of the solution and the gloss of the film. physical properties.

It has improved water resistance, etc., and is particularly inexpensive without impairing the physical properties of expensive casein.

To prepare the composition of the present invention 9 For example, a method of mixing modified Pv^ dissolved in aqueous water and casein dissolved in water made alkaline with aqueous ammonia, soda ash, etc.; Modified PVA in alkaline water
A method of adding and heating a mixture of casein and casein, modified P
A method may be adopted in which a premixed mixture of salts such as VA, casein, and soda ash is added to water and dissolved.

The composition of the present invention can maintain a uniform state for a long time when made into an aqueous solution, and has the excellent mechanical properties, protective colloidal properties, adhesive properties, etc. of modified PVA, and the excellent water resistance of casein. It has characteristics such as the ability to disperse and disperse pigments. For example, when the composition of the present invention is made into a film from an aqueous solution.

It has good transparency and mechanical properties, and has excellent ability to disperse pigments and improve the mechanical stability of latex.Furthermore, when made into fibers, it has excellent dyeability and one-fold shrinkage. It has robustness.

As described above, the composition of the present invention can maintain a stable and uniform state for a long time when made into an aqueous solution, so it can be widely used in applications that take advantage of the characteristics of both components.

For example, the composition of the present invention can be used as an adhesive for bonding paper, for attaching labels to beer bottles, canned cans, etc., as a protective colloid and thickener for latex, and as a pigment binder for paper manufacturing machines.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A saponified product of α-dodecene-vinyl acetate copolymer with an α-dodecene content of 0.15 mol% (degree of saponification 88 mol%) was added to water, and heated and melted to obtain 4% by weight of modified PVA. An aqueous solution was prepared.

Meanwhile, lactic acid casein was added to the ammonia water.

A 4% by weight aqueous solution of casein was prepared by stirring.

The aqueous solution of type 2 above was prepared with a weight ratio of modified PVA and casein of 9:i, 7:a, 5:3, 3:1°1:
9 to prepare a composition.

The following tests were conducted on the obtained composition.

First, the aqueous solution was allowed to stand at room temperature for 7 days, and the storage stability of the aqueous solution was determined by observing the state of separation of the components. In addition, a film with a thickness of 40 μm was obtained by forming an aqueous solution, and the uniformity of the film was determined by measuring the particle size of the islands in the sea-island structure using a microscope. After conditioning the humidity with atmospheric extraction at 965% RH at °C, the tensile strength and tensile elongation were measured at a tensile speed of 50 mm/min. Furthermore, the mechanical stability of latex was tested using a 4% by weight aqueous solution as follows. That is, take 50 g of a commercially available polyvinylidene chloride latex (solid content 45%) mixed with 1 l of a 4 wt % aqueous solution, and
Under a load of 15g using a Ron type mechanical stability tester,
After grinding for 15 minutes under the conditions of 1000 r, p, m.

The weight percent of aggregates remaining on the sieve was determined.

These results are shown in Tables 1-3.

Furthermore, Tables 1 and 3 also show the results for cases in which only modified PVA or only casein was used as control examples.

Note that when the latex alone was tested without using the composition of the present invention, the mechanical stability test result of the latex was 0.
It was 6% by weight.

Example 2 Same as Example 1 except that PVA modified with lauryl vinyl ether (containing lauryl vinyl ether 10.25 mol%, degree of saponification 96 mol%) was used instead of Pν8 modified with α-dodecene. A composition was prepared and tested in the same manner as in Example 1.

The results of Gore et al. and the results of the control example are shown in Tables 1 to 3 together.

In addition, the obtained film was heat treated at 120''c for 5 minutes, then immersed in water at 20°C, and the elution rate of the film was measured after 20 minutes.The results are shown in Table 4 along with a control example.

Comparative Example 1 Commercially available PVA was used instead of PVA modified with α-dodecene
The test was conducted in the same manner as in Example 1 except that (degree of polymerization ↑ 720, degree of saponification 88 mol%) was used. The results are shown in Table 1~
Shown in 3.

As is clear from Tables 1 to 4, the compositions of the present invention are superior in aqueous solution storage stability, film uniformity, and mechanical properties compared to the comparative examples.

In terms of water resistance, ability to improve mechanical stability of latex, etc., it has extremely well-balanced performance compared to comparative examples and control examples.

r 7 7 7’T mI].

1 l 1 1 1 1'Xl○10IX1 1 1-1 1 1 1 1 1, -. 1 1 1 111\l
◎I◎l<11 1 1”l l l 1Table 2 Table 3 Table 4

Claims (1)

[Scope of Claims] (]) A long chain alkyl group having 4 to 20 carbon atoms;
10 mol% and 1 to 99% by weight of water-soluble long-chain alkyl group-modified polyvinyl alcohol (A). A polymeric composition comprising 99 to 1% casein (B) by weight.